sabi notes
http://WWW.sabi.co.UK/
Notes mostly about Linux and computer issuesen-GBhttp://blogs.law.Harvard.edu/tech/rss/notes {at} notes.for.sabi.co.UKCopyright 2006 Peter G.14000AMDIntelMicrosoftNintendoSonyCPUOSVoIPfile sytemfree softwarehardwareperformancesystem administrationvideogamesvirtual memoryALSADebianFedoraGNUJFSKDELinuxMS Windows 2000MS Windows XPMS WindowsPS/3RedHatSUSEUNIXXFSXbox 360ext3Mon, 22 Jan 2007 21:05:00 +0000Crazily high cable prices
http://WWW.sabi.co.UK/blog/0701jan.html?070122#070122
Spotted impressively high prices for ordinary
computer cables. Online too.cablesshoppinghttp://www.sabi.co.uk/blog/0701jan.html?070120#070120bMon, 22 Jan 2007 21:00:00 +0000Simple configuration-driving environment variables
http://WWW.sabi.co.UK/blog/0701jan.html?070120#070120b
A few environment variables can be a nice
orthogonal base for configuration space, especially
shell-script configuration files.UNIXLinuxsystem administrationshellhttp://www.sabi.co.uk/blog/0701jan.html?070120#070120bSat, 20 Jan 2007 23:15:00 +0000Impressive FireWire 800 performance
http://WWW.sabi.co.UK/blog/0701jan.html?070120#070120
Amazing performance of FireWire 800, where the same
disk runs 2-3 times as fast with it than with FireWire 400 or
USB2, and at speeds near those of SATA.storagehardwareUSB2SATAUSB2IEEE1394FireWirehttp://www.sabi.co.uk/blog/0701jan.html?070120#070120Sat, 20 Jan 2007 09:55:00 +0000Trying two recent branded external hard drives
http://WWW.sabi.co.UK/blog/0701jan.html?070115#070115
I have just tried two branded external USB2 hard
drives, and they seem to work fine, and fairly quickly, and
without the power supply issues that come from underspecified
power bricks. But eSATA is going to be hopefully much
better.storagehardwareUSB2SATAUSB2IEEE1394FireWirehttp://www.sabi.co.uk/blog/0701jan.html?070115#070115Mon, 15 Jan 2007 22:25:00 +0000Parallel system with low power multi-CPU chips
http://WWW.sabi.co.UK/blog/0701jan.html?070108#070108
SiCortex has launched massively parallel low power
systems based in 6-CPU MIPS chips based on the idea that low
power is good and memory stalls are bad.architecturehardwareparallelCPUhttp://www.sabi.co.uk/blog/0701jan.html?070108#070108Mon, 08 Jan 2007 22:10:00 +0000The DNS, interfaces, nodes, directories and naming schemes
http://WWW.sabi.co.UK/blog/0701jan.html?070105#070105
The DNS is a hierarchical linearized scheme for
naming interfaces, not computers or other nodes. But people
don't think in terms of interfaces, and nodes with multiple
interfaces on multiple subnets pose some naming issues. Some
alternatives are briefly discussed.networkingsysadmInternetDNSnaminghttp://www.sabi.co.uk/blog/0701jan.html?070105#070105Fri, 05 Jan 2007 21:45:00 +0000Per-node servers and interposition, and the DNS
http://WWW.sabi.co.UK/blog/anno06-4th.html?061231#061231
Putting in per-node caching or proxy servers is a
form of non-transparent static interposition, a technique which
in its general form is rarely available but results in great
flexibility. It is related to advising and 'become:' in
programming languages, and to DNS service discovery
standards.networkinglanguagessysadmDNShttp://www.sabi.co.uk/Notes/anno06-4th.html#061231Sun, 31 Dec 2006 23:20:00 +0000Fighting with YumEx and Yum
http://WWW.sabi.co.UK/blog/anno06-4th.html?061230#061230b
Using YumEx and Yum to set up a laptop with a lot of
tools, and suffering because of their slowness and limitations.
Things could be better than this...RedHatFedoraperformanceLinuxhttp://www.sabi.co.uk/Notes/anno06-4th.html#061230bSat, 30 Dec 2006 20:10:00 +0000Amazing networking performance
http://WWW.sabi.co.UK/blog/anno06-4th.html?061230#061230
Some simple speed tests show that current top end
CPUs and system can transmit at full speed on 1gb/s wires even
without jumbo frames as they can sustain amazingly high interrupt
and context switch rates, and intelligent network adapters
help.networkingperformanceLinuxhttp://www.sabi.co.uk/Notes/anno06-4th.html#061230Sat, 30 Dec 2006 11:50:00 +0000Difference between Smalltalk-72 and -76, why it matters
http://WWW.sabi.co.UK/blog/anno06-4th.html?061227#061227
Smalltalk-72, Smalltalk-76, the big difference
between message passing and overloading why it matters,
and many CPUs on the same chip.programmingsoftware engineeringobject orientedoverloadingmessage passinghttp://www.sabi.co.uk/Notes/anno06-4th.html#061227Wed, 27 Dec 2006 15:10:00 +0000Rapid or less painful switching of service provider
http://WWW.sabi.co.UK/blog/anno06-4th.html?061226#061226b
It is often useful to run caching or slave servers on
all clients so that most server addresses can be configured as
127.0.0.1 as reconfiguring and restarting servers is often a lot
quicker and less painful than reconfiguring and restarting
applications.sysadmserversnetworkingInternetEthernethttp://www.sabi.co.uk/Notes/anno06-4th.html#061226bTue, 26 Dec 2006 21:55:00 +0000Looking again at centralized vs. localized servers: why, where
http://WWW.sabi.co.UK/blog/anno06-4th.html?061226#061226
Centralized vs. localized service depends on a table
of service vs. level of redundancy. Partitioning it into
subtables and then reading it by rows or columns gives different
service structures. Many services have dependencies, therefore
it is pointless to have independent redundancy for them. In
general the idea of bringing servers nearer to the point of
delivery, usually a workgroup, is indeed reasonable according to
some plausible criteria.sysadmserversnetworkingInternetEthernethttp://www.sabi.co.uk/Notes/anno06-4th.html#061226Tue, 26 Dec 2006 14:40:00 +0000Message passing and overloading
http://WWW.sabi.co.UK/blog/anno06-4th.html?061224#061224
Smalltalk-72, Smalltalk-76, the big difference
between message passing and overloading, and terminology
confusion.programmingsoftware engineeringobject orientedoverloadingmessage passinghttp://www.sabi.co.uk/Notes/anno06-4th.html#061224Sun, 24 Dec 2006 13:55:00 +0000OO, overloading and genericity
http://WWW.sabi.co.UK/blog/anno06-4th.html?061223#061223
What are overloading and genericity and their
relationship to OO.programmingsoftware engineeringobject orientedmodulesoverloadinggenericityhttp://www.sabi.co.uk/Notes/anno06-4th.html#061223Sat, 23 Dec 2006 18:20:00 +0000Tomcat 5 configuration for multiple ports
http://WWW.sabi.co.UK/blog/anno06-4th.html?061216#061216
Tomcat has a slightly odd way of resolving request
URLs into servlets. Binding different ports on the same domain
to different default servlets requires a somewhat unusual
configuration, but it is useful for one-to-one URL forwarding
from an Apache front-end via AJP.sysadmLinuxApacheTomcatwebhttp://www.sabi.co.uk/Notes/anno06-4th.html#061216Sat, 16 Dec 2006 20:35:00 +0000More on large bridged network and centralized servers
http://WWW.sabi.co.UK/blog/anno06-4th.html?061212#061212
More details about VLANs: bridged VLANs are often
partitioned by VLAN tagging, two opposite but complementary
techniques. These are often used together in large networks, which
mostly means inter-site and even international ones, both to take
advantage of large broadcast domains and mitigate their effects,
especially when servers and services are
centralized.networkingsysadmLinuxNFSVLANEthernethttp://www.sabi.co.uk/Notes/anno06-4th.html#061212Tue, 12 Dec 2006 21:45:00 +0000TCP: data reliable, signaling not reliable
http://WWW.sabi.co.UK/blog/anno06-4th.html?061210#061210b
Some application problems are explained by pointing
out that while TCP transport is reliable, signaling is not, and
anyhow TCP under Linux has a very long and excessive timeout for
detecting a dead connection.networkingInternetTCPNFSLinuxhttp://www.sabi.co.uk/Notes/anno06-4th.html#061210bSun, 10 Dec 2006 19:20:00 +0000Large bridged networks with centralized servers
http://WWW.sabi.co.UK/blog/anno06-4th.html?061210#061210
Large network infrastructures based on bridging and
central servers are often the result of hasty attempts to scale
up smaller infrastructures. They may seem to work, but I think
that they are fragile and inefficient. I reckon that workgroup
servers and local services are preferable. Difficult choices
anyhow about home directories and laptops.networkingsysadmLinuxNFSVLANEthernethttp://www.sabi.co.uk/Notes/anno06-4th.html#061210Sun, 10 Dec 2006 17:35:00 +0000Updated IP shaping script
http://WWW.sabi.co.UK/#sourcesSabishape?061126
While the logic of my traffic shaping setup script has not
changed much, this update contains many adjustments to details
that should improve it a fair bit.
LinuxnetworkingNetfilteriptablesshellshapingIPconfigurationtraffic controlSun, 26 Nov 2006 15:30:00 +0000How long does it take for a standard PC to become fatally infected
http://WWW.sabi.co.UK/blog/anno06-4th.html?061111#061111
An article reports that after a rather short time of
being connected to the Internet and browsing an unprotected
installation of MS Windows XP gets infected with very many
trojans, spyware, ... programs.MicrosoftInternetsecurityspywarehttp://www.sabi.co.uk/Notes/anno06-4th.html#061111Sat, 11 Nov 2006 22:05:00 +0000Impressions from LinuxWorld Expo 2006, London
http://WWW.sabi.co.UK/blog/anno06-4th.html?061105#061105
Belated impressions from the recent Linux World Expo
in London.LinuxIBMRedHatNovellsystem administrationnetwork administrationhttp://www.sabi.co.uk/Notes/anno06-4th.html#061105Sun, 05 Nov 2006 22:35:00 +0100Very high spyware and trojan infection rates
http://WWW.sabi.co.UK/blog/anno06-4th.html?061103#061103f
A study (from an interested party) reports very,
very high rates of spyware and trojan infections. Owning
someone else's computer can be quite profitable.securityMS Windowsprivacyhttp://www.sabi.co.uk/Notes/anno06-4th.html#061103fFri, 03 Nov 2006 22:10:00 +0100FireWire over Ethernet style wiring
http://WWW.sabi.co.UK/blog/anno06-4th.html?061103#061103e
Just discovered a standard to run the FireWire bus
protocol over 1000gb/s Ethernet wiring. Quite an interesting
combination.cablingFireWireEthernethttp://www.sabi.co.uk/Notes/anno06-4th.html#061103eFri, 03 Nov 2006 21:55:00 +0100Outsourcing incentives to stagnation
http://WWW.sabi.co.UK/blog/anno06-4th.html?061103#061103d
A pundit points out that outsourcing often results in
high incentives to stagnation for the outsourcing
supplier.sociologybusinessoutsourcinghttp://www.sabi.co.uk/Notes/anno06-4th.html#061103dFri, 03 Nov 2006 21:40:00 +0100Lots of lost laptops
http://WWW.sabi.co.UK/blog/anno06-4th.html?061103#061103c
An article reports amazing numbers of lost laptops,
of which few are reclaimed, because managers prefer to get a new
new than wasting time in recovering the old one.securitysociologyhttp://www.sabi.co.uk/Notes/anno06-4th.html#061103cFri, 03 Nov 2006 21:35:00 +0100Shoddy mechanical design for connectors
http://WWW.sabi.co.UK/blog/anno06-4th.html?061103#061103b
Some connector designs are ptrone to breaking off,
and this is bad particularly for sockets. FireWire connectors
were designed well though.designqualitymechanicalconnectorhttp://www.sabi.co.uk/Notes/anno06-4th.html#061103bFri, 03 Nov 2006 21:20:00 +0100John C. Dvorak on CSS
http://WWW.sabi.co.UK/blog/anno06-4th.html?061103#061103
A pundit points out that CSS is a very dense and
compact languages, and mishaps like poor implementation have
wide effects.webCSSHTMLhttp://www.sabi.co.uk/Notes/anno06-4th.html#061103Fri, 03 Nov 2006 21:05:00 +0100Important details to consider as to digital cameras
http://WWW.sabi.co.UK/blog/anno06-4th.html?061101#061101
Some small attributes of digital cameras are actually
quite relevant, like having an external flash socket.photographydigitalcamerahttp://www.sabi.co.uk/Notes/anno06-4th.html#061101Wed, 01 Nov 2006 21:40:00 +0100EMC2 often recommends RAID3
http://WWW.sabi.co.UK/blog/anno06-4th.html?061031#061031b
Just found out that often EMC2, a noted storage
system manufacturer, defaults to RAID3 or a variant.RAIDstoragehttp://www.sabi.co.uk/Notes/anno06-4th.html#061031bTue, 31 Oct 2006 21:10:00 +0100Storage wire and command protocols, and SAN vs. NAS
http://WWW.sabi.co.UK/blog/anno06-4th.html?061031#061031
Commenting on a discussion about the difference
between the two levels of storage protocols (link and command)
and why bother with SANs as NAS is possible.NASSANSCSIATAhttp://www.sabi.co.uk/Notes/anno06-4th.html#061031Tue, 31 Oct 2006 20:15:00 +0100Teknik posture chair review
http://WWW.sabi.co.UK/Notes/hwNotesReviews.html#teknikPosture?061022
Using a "kneeling chair" to site somewhat high while
not putting weight on the thighs.hardwareseatingergonomicsSun, 22 Oct 2006 18:40:00 +0100File system notes updates
http://WWW.sabi.co.UK/Notes/linuxFS.html?061022
Some updates to the bibliography section and the
links section of my file system for Linux notes.LinuxRAIDXFSJFSfile systemSun, 22 Oct 2006 17:45:00 +0100RAID5 perversions
http://WWW.sabi.co.UK/blog/anno06-4th.html?061022#061022b
A list of quotes showing that some people misuse
RAID5 as in 15+1 disc drive configurations, or worse.LinuxRAIDXFSfile systemhttp://www.sabi.co.uk/Notes/anno06-4th.html#061022bSun, 22 Oct 2006 17:10:00 +0100XFS etc. performance for parallel IO and fragmentation
http://WWW.sabi.co.UK/blog/anno06-4th.html?061022#061022
A pointer to and some comments on a very interesting
paper showing some large recent improvements in XFS performance
on a parallel system with multiple concurrent reads and writes.
Some surprising comparisons with JFS and other file
systems.LinuxXFSJFSfile systemhttp://www.sabi.co.uk/Notes/anno06-4th.html#061022Sun, 22 Oct 2006 16:05:00 +0100Options for mailboxing and tagged queueing
http://WWW.sabi.co.UK/blog/anno06-4th.html?061015#061015
I have recently had a look and upgraded a bit a small
video-on-demand system that I first set-up about 10 years ago.
Amusing to see how hardware had evolved in the meantime, and why
I chose certain components may be interesting.architecturehardwarevideomoviesSCSInetworkhttp://www.sabi.co.uk/Notes/anno06-4th.html#061015Sun, 15 Oct 2006 11:50:00 +0100Effect of elevator on multistream reading performance
http://WWW.sabi.co.UK/blog/anno06-4th.html?061014#061014
Some more experiments with multiple concurrent stream
reading from a disc. Turns out that the 'anticipatory' elevator
in Linux maintains aggregate bandwidth by sorting and batching
requests, a bit cruder but overall with the same results as
tagged queueing.architecturehardwarevideomoviesSCSInetworkhttp://www.sabi.co.uk/Notes/anno06-4th.html#061014Sat, 14 Oct 2006 08:55:00 +0100Evolution of a video-on-demand system
http://WWW.sabi.co.UK/blog/anno06-4th.html?061013#061013
I have recently had a look and upgraded a bit a small
video-on-demand system that I first set-up about 10 years ago.
Amusing to see how hardware had evolved in the meantime, and why
I chose certain components may be interesting.architecturehardwarevideomoviesSCSInetworkhttp://www.sabi.co.uk/Notes/anno06-4th.html#061013Fri, 13 Oct 2006 17:10:00 +0100Another technique called "HDR" somewhat improperly
http://WWW.sabi.co.UK/blog/anno06-4th.html?061004#061004
In video games HDR rendering means doing intermediate
lighting calculations with higher range than that used for final
output, to prevent clipping due to overflow and underflow. This
could be done by more careful staging of calculations, but it
also delivers higher precision, not range, which helps with
multipass algorithmsarchitecturehardwaregraphicsvideogamesNVIDIAhttp://www.sabi.co.uk/Notes/anno06-4th.html#061004Wed, 04 Oct 2006 19:10:00 +0100Games HDR, photos range compressions, and terminology
http://WWW.sabi.co.UK/blog/anno06-4th.html?061003#061003
Discovered High Dynamic Range photography, which is
interesting but misnomed, unlike High Dynamic Range in
videogames, which is truer to its name.architecturehardwaregraphicsvideogamesNVIDIAhttp://www.sabi.co.uk/Notes/anno06-4th.html#061003Tue, 03 Oct 2006 23:45:00 +0100Intel researching chip with 80 FPUs
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060928#060928c
Intel has been talking about a very fast chip with 80
FPUs to be delivered in about 5 years. There is also already
available the ClearSpeed CSX600 with 96 FPUs, but apparently it
is much more expensive.architecturehardwareCPUIntelhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060928cThu, 28 Sep 2006 22:35:00 +0100Updates to the hardware notes and reviews
http://WWW.sabi.co.UK/Notes/hwNotesReviews.html#belkinF5D7630?060928
Updated the review of the Belkin F5D7630 with further
condemnation of the poor quality of its firmware, especially
after loading on it the much better firmware of the compatible
SMC 7804WBRA.ADSLqualityhardwarenetworkingsystem administrationThu, 28 Sep 2006 18:40:00 +0100Fixing Belkin ADSL gateway bugs by using SMC firmware
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060928#060928b
My Belkin F5D7630 ADSL modem/router has always been
buggy, but I managed to work around most bugs. Being fed up with
it, I loaded on it the firmware from the compatible SMC 7804WBRA
and what a difference. It seems clear to me that while Belkin
and SMC used the same source, SMC spent some effort in testing
and fixing the firmware, and documenting it well. Makes me wish
I bought the SMC model.ADSLqualityhardwarenetworkingsystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060928bThu, 28 Sep 2006 18:15:00 +0100Configuring 'automount' to use '/etc/fstab'
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060928#060928
The Linux 'automount' daemon is quite convenient but
is uses a different mount map format from '/etc/fstab'. But it
can get the mount map by running a program, and it is was to
write a script to convert '/etc/fstab' entries into 'automount'
map ones on the line, and this preserves the flexibility and
maintainability of keeping all mount configuration in one
place.UNIXLinuxfilesystemssystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060928Thu, 28 Sep 2006 18:00:00 +0100Some reports on dual core versus hyperthreading performance
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060924#060924c
Spotted a couple on entries in the PostgreSQL mailing
list comparing dual core AMD verbus hyperthreading Intel CPUs
for running that highly parallel DBMS. AMD dual core looks good,
but surprisingly so does hyperthreading.LinuxApacheAMDAthlonOpteronperformancehttp://www.sabi.co.uk/Notes/anno06-3rd.html#060924Sun, 24 Sep 2006 23:05:00 +0100IBM to deliver hybrid Opteron and Cell cluster
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060924#060924b
IBM will deliver a 32,000 CPU Linux based cluster
where half of the elements will be Opteron based and half Cell
based, and claim that some new software infrastructure will help
manage the cluster.LinuxOpteronAMDIBMCellclusterperformancehttp://www.sabi.co.uk/Notes/anno06-3rd.html#060924bSun, 24 Sep 2006 22:10:00 +0100Web transaction test shows 64b slower than 32b
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060924#060924
Some recent report shows that the same large scale
web benchmark on system with 2 Opteron CPUs runs noticeable faster
in 32b than 64b mode for between 128 and 100 and 400 clients.
Comparing with a similar report for a test for 2 Athlon MP CPUs
it looks like the reason is memory: the same program compiled
for 32b mode uses less memory, and memory bandwidth, than in 64b
mode.LinuxApacheAMDAthlonOpteronperformancehttp://www.sabi.co.uk/Notes/anno06-3rd.html#060924Sun, 24 Sep 2006 19:45:00 +0100Polipo, another nice proxy cache for small sites
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060920#060920b
A pointer to Polipo, a nice and featureful proxy
cache one might want to consider as an alternative to Apache or
Squid, especially for IPv6 sites.SquidApacheprogrammingInternetsystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060920bWed, 20 Sep 2006 23:05:00 +0100Using Apache 2.2 as a proxy cache, with patch
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060920#060920
For various reasons I am now using Apache as a proxy
cache instead of Squid. This has required fixing some bugs and
extending a bit the Apache caching module.SquidApacheprogrammingInternetsystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060920Wed, 20 Sep 2006 08:40:00 +0100IPv6 prefix non-portability and unique local addresses
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060917#060917c
According to one argument, local IPv6
addresses have the advantage of being portable. But only
in the sense of always requiring NAT to a non-portable prefix.
An old non-portable global prefix can also be NAT'ed to
a new different non-portable global prefix.networkInternetIPv6NATsystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060917cSun, 17 Sep 2006 23:35:00 +0100Reintroducing private addresses, and/or NAT, in IPv6
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060917#060917b
Some network administrators would like to have
something like IPv4 private addresses and NAT in IPv6; a couple
of ways have been proposed to achieve something like that, but
things could be simpler, understanding what is the real goal,
which is not private addresses or NAT as such.networkInternetIPv6NATsecuritysystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060917bSun, 17 Sep 2006 18:10:00 +0100Weird and not so weird long standing bugs
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060917#060917
It is somewhat amazing that some minor but annoying
bugs have remained in some very popular applications for several
years. I haven't fixed them myself simply to avoid maintaining
my own patches, and I haven't reported them to avoid the
hassle.programmingKDEEmacssystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060917Sun, 17 Sep 2006 17:35:00 +0100Large IPv6 datagram sizes and why they matter
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060916#060916
Why IPv6 larger datagram sizes matter when
link bandwidths are high, not just window size when
latency is also high.networkInternetIPv6system administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060916Sat, 16 Sep 2006 11:20:00 +0100Thousands of queries per second for private addresses
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060915#060915
The root DNS servers get thousands of queries
per second about site local private address ranges. As
Stonebraker learned decades ago, misconfigured servers
and networks are the norm, not the exception.networkInternetDNSDBMSperformancesystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060915Fri, 15 Sep 2006 08:35:00 +0100Game load times, fragmentation; reporting to base
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060914#060914b
Using statistics collected from Steam users,
Valve has discovered that poor game loading times depend
a lot of fragmentation. Also means they scan users disks
and report that back.videogamesbusinessperformancefile systemshttp://www.sabi.co.uk/Notes/anno06-3rd.html#060914bThu, 14 Sep 2006 19:25:00 +0100Episodic game content four times cheaper to develop
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060914#060914
Valve reports that developing new episodes of
an already developed game is four times cheaper. Also,
that World of Warcraft is the benchmark.videogamesbusinessmiddlewareMMORPGhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060914Thu, 14 Sep 2006 19:10:00 +0100Socket duty cycles matter
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060913#060913b
The designers of the original FireWire
connectors designed them to be resistant to repeated
plugging/unplugging. The number of insertion cycles for
which sockets are rated is indeed in general an
important and underrated topic.hardwareFireWireIEEE1394securitydebuggingsystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060913bWed, 13 Sep 2006 20:05:00 +0100Astonishing FireWire security vulnerability
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060913#060913
Most FireWire host adapters offer excessive accessive
access to their host's memory, and devices can initiate
operations because FireWire is essentially P2P. This can be
turned to advantage for debugging.hardwareFireWireIEEE1394securitydebuggingsystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060913Wed, 13 Sep 2006 19:25:00 +0100IPv6 options for IPv4 interoperability
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060911#060911
More on IPv6, the practical options to get IPv6
connectivity.networkInternetIPv6securitysystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060911Mon, 11 Sep 2006 22:30:00 +0100QoS shaping and a nice paper with a strange setup
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060910#060910b
Found a nice paper about QoS with Linux using the
LARTC framework. Interesting observations about sampling rate.
But puzzling setup of an example: incoming shaping is done at
the gateway egree interface, not the ingress one.LinuxLARTCnetworkInternetQoSsabishapesystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060910bSun, 10 Sep 2006 20:40:00 +0100Using IPv6 for a large site
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060910#060910
While chatting about network management at a large
scientific site IPv6 was mentioned. I quite like it, and anyhow it
is going to become indispensable soon. It also has some nice
advantages by design, and some serendipitous ones.networkInternetIPv6securitysystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060910Sun, 10 Sep 2006 18:05:00 +0100Good value large can of grapefruit segments
http://WWW.sabi.co.UK/Notes/miscShopping.html#princesGrapefruitLarge
Just discovered my local Coop has a 1.25kg
can of grapefruit segments for a good price. Excellent
value.shoppingfoodhttp://www.sabi.co.uk/Notes/miscShopping.html#princesGrapefruitLargeMon, 11 Sep 2006 18:55:00 +0100A new 'init' design from Ubuntu
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060828#060828
The Ubuntu project is going to replace the ugly
System V style 'init' with 'upstart', which will be a general
process manager, replacing 'cron' and 'inetd' as well. Seems
a bit of a mess to me, but let's hope it is not.UNIXLinuxpragmaticssystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060828Mon, 28 Aug 2006 23:45:00 +0100Much better performance with direct HyperTransport interface
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060825#060825
There are now motherboards with a direct
HyperTransport interface called HTX, and performance seems to be
much higher than PCI-E for high traffic network and probably
most other coprocessors.hardwareCPUAMDIntelbushttp://www.sabi.co.uk/Notes/anno06-3rd.html#060825Fri, 25 Aug 2006 22:40:00 +0100AMD hopes for large market share in servers
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060822#060822
AMD hopes for a 40% market share in servers, where it
has the advantage because of HyperTransport. Intel instead
dominates laptops, especially with Core 2 Duo, and low end
desktops with integrated graphics.hardwareCPUAMDIntelhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060822Tue, 22 Aug 2006 22:05:00 +0100The 32-bit Linux real and virtual memory boundaries
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060821#060821c
The x86 Linux kernel maps real memory into the
address space of each process, and there is a performance
advantage in the ability to map all of real memory in every
process. On 32-bit CPUs the address space is limited to 4GiB,
so one needs to decide how much to use to map real memory and
how much for the use of each process.Linuxkernelmemoryvirtual memoryhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060821cMon, 21 Aug 2006 23:45:00 +0100Another chip with 16 CPUs
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060821#060821b
Just seen another chip with 16 CPUs, this one
not quite there yet but with the aim of having a grid
style architecture.architecturehardwareCPUMIPSLinuxgridhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060821bMon, 21 Aug 2006 13:35:00 +010015 years of Linux
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060821#060821
Linux was first announced 15 years ago. It is
a long time, and perhaps Plan 9 or BSD should have
enjoyed its popularity. But it is good enough and its
licence is the GPL.Linuxkerneloperating systemGPLBSDUNIXhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060821Mon, 21 Aug 2006 09:40:00 +0100A chip with 16 CPUs
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060815#060815
Movidis is selling a server based on a low
power 16-CPU chip by Cavium. Interesting tradeoffs,
looks like (and I hope it is) a winner.architecturehardwareCPUMIPSLinuxhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060815Tue, 15 Aug 2006 18:15:00 +0100Updates to the font notes
http://WWW.sabi.co.UK/Notes/linuxFonts.html#appBlog?060813
Some updates to my fonts notes and the addition of a new
section with pointers to font related entries in my blog.XLinuxUNIXfontsSun, 13 Aug 2006 21:05:00 +0100Finer tagging of text in HTML and the semantic web
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060810#060810b
My own conventions for tagging various parts of speech
and types of discourse when I write HTML.XMLHTMLSGMLmarkuphttp://www.sabi.co.uk/Notes/anno06-3rd.html#060810bThu, 10 Aug 2006 22:20:00 +0100 Fonts, antialiasing and low DPI
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060810#060810
While in general I reckon that font
antialiasing is not a good idea and is unnecessary, on low
DPI screen it can be the least bad of a bad lot. Also,
some hints on how to scale up fonts on high DPI
monitors.LinuxfontsantialiasingX window systemhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060810Thu, 10 Aug 2006 21:40:00 +0100XML and HTML microformats
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060809#060809
Microformats are an objectionable way of
describing data not with XML tags, but with HTML
attributes. That is not quite nice. But much of the same
effect can be obtained by describing text with HTML tags,
and help data processing programs with
attributes.XMLHTMLSGMLmarkuphttp://www.sabi.co.uk/Notes/anno06-3rd.html#060809Wed, 09 Aug 2006 19:05:00 +0100What is the resident set size, 'exmap' and working sets
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060808#060808
The Linux resident set size of processes, a better way to
compute it, and what would be a much better way to define it.
Linuxoperating systemspagingmemory managementhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060808Tue, 08 Aug 2006 20:55:00 +0100Restructuring of the front page
http://WWW.sabi.co.UK/?060807
My site front page has been restructured (the
content is almost the same) to use tables instead of
lists, as that seems slightly more readable.webhtmldesignMon, 07 Aug 2006 15:20:00 +0100Solved problem with automounted filesystems and 'updatedb'
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060806#060806c
The 'mlocate' version of 'updatedb' will not
descend into an empty directory, and automounter mount
points look like empty directories. The better solution is
to change how 'updatedb' is used, to have a list of
filesystems it should scan and a 'locate' database for
each one (usually in each one).UNIXLinuxfilesystemssystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060806cSun, 06 Aug 2006 23:50:00 +0100The 'init' daemon and 'inittab'
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060806#060806b
I am quite unhappy about the current
structure of the GNU/Linux startup system, based on a
misdesigned corruption of the original System V 'init'
scheme. Which should be fixed, not corrupted, or replaced
with something better.UNIXLinuxpragmaticssystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060806bSun, 06 Aug 2006 23:10:00 +0100An amusing example of (moderately) bad code
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060806#060806
Just spotted some (moderately) bad code in some kernel IDE
driver. All too typical unfortunately.
Linuxsoftware engineeringpragmaticsprogramminghttp://www.sabi.co.uk/Notes/anno06-3rd.html#060806Sun, 06 Aug 2006 16:40:00 +0100Using automounter maps instead of '/etc/fstab'
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060805#060805
Static mounting via '/etc/fstab' can be replaced with dynamic
mounting via 'autofs' and there are some reasonable advantages.
Linuxfilesystemspartitionssystem administrationhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060805Sat, 05 Aug 2006 23:25:00 +0100Small updates to my KDE startup script
http://WWW.sabi.co.UK/#sourcesDokde?060805
My alternative (to 'startkde') KDE startup is not updated for
KDE 3.5.3, which has a slightly different startup sequence. It
also contains a couple of fixes to bugs in 'startkde'.
LinuxKDEscriptshellSat, 05 Aug 2006 17:10:00 +0100Added review of the game "Sniper Elite"
http://WWW.sabi.co.UK/Notes/miscGames.html#gameSniper?060729
Reviewed the "Sniper Elite" game and slightly edited
some of the other game reviews.
videogamesgamesreviewshttp://WWW.sabi.co.UK/Notes/miscGames.html#gameSniper?060729Sat, 29 Jul 2006 13:30:00 +0100Using humans as information system components
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060728#060728b
architecturesystem designpattern matchingweb serviceshttp://www.sabi.co.uk/Notes/anno06-3rd.html#060728bFri, 28 Jul 2006 16:30:00 +0100A bitter irony in the design of 'udev'
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060728#060728
The 'sysfs' file system defines files that for each
device state which major and minor numbers its device
files should have, but does not actually define the
device file itself.
Linuxkerneludevdevfshttp://www.sabi.co.uk/Notes/anno06-1st.html#060728Fri, 28 Jul 2006 14:45:00 +0100CPU bound modern games and top end GPUs
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060727#060727b
Comparing recent CPUs on recent games, these seem rather
CPU bound.
gamesvideogamesAthlonCore 2graphicsCPUNVIDIAAMDIntelhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060727bThu, 27 Jul 2006 23:25:00 +0100Desktop GNU/Linux is better with 1GiB of RAM
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060727#060727
Another user has sold out and discovered that desktop GNU/Linux
performs a lot better with 1GiB than with 512MiB of RAM.
LinuxRAMECC1GiBswappingvirtual memoryKDEhttp://www.sabi.co.uk/Notes/anno06-1st.html#060727Thu, 27 Jul 2006 22:15:00 +0100Another symptom of the Microsoft cultural hegemony
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060726#060726
Many people seem to think that in GNU/Linux command
options should be last, just as in MS Windows.
UNIXLinuxMS Windowshttp://WWW.sabi.co.UK/Notes/anno06-3rd.html#060726Wed, 26 Jul 2006 23:05:00 +0100Interview with the CEO of NVIDIA
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060725#060725b
The CEO of NVIDIA speaks about programmability in
graphics cards, and approves the Blu-Ray drive in the
PS3, and the large investments companies have to put in
development with a 6 month product generation cycle.
PCgamesgraphicsNVIDIAPS/3http://WWW.sabi.co.UK/Notes/anno06-3rd.html#060725bTue, 25 Jul 2006 22:35:00 +0100ATi and AMD merge
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060725#060725
Some comments on the AMD and ATi merger, which seems to
me a bit strange, because the two companies are really
not that related. I suspect that it is mainly a reaction
to Intel's dominance of the integrated chipset market.
PCgamesgraphicsVGAAMDATihttp://WWW.sabi.co.UK/Notes/anno06-3rd.html#060725Tue, 25 Jul 2006 21:15:00 +0100Mark Rein on games on laptops and Intel graphics chipsets
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060724#060724d
Mark Rein complains with some causes that most laptops
and many desktops are sold with Intel graphics chips
that cannot run the latest games, including those from
his company. Too bad that game companies don't feel like
selling to the majority of the market though. probably
the issue is games with too much geometry, which is not
as easily scalable as effects.
PCgamesgraphicsVGAhttp://WWW.sabi.co.UK/Notes/anno06-3rd.html#060724dMon, 24 Jul 2006 22:50:00 +0100Getting software into the Linux kernel
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060724#060724c
Controlling Linux kernel and base user level sources is
precious, and some sources are merged in with a lot less
fuss than others.
LinuxkerneludevReiser4XFShttp://WWW.sabi.co.UK/Notes/anno06-3rd.html#060724cMon, 24 Jul 2006 21:55:00 +0100Partitions, extended partitions and 'ms-sys -p' on NTFS
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060724#060724b
The GNU/Linux utility 'ms-sys -p' fixes a number of
partition issues for MS Windows, but it damages NTFS
filesystems.
LinuxpartitionsMS WindowsNTFShttp://WWW.sabi.co.UK/Notes/anno06-3rd.html#060724bMon, 24 Jul 2006 21:35:00 +0100Very odd extra 16 bytes
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060724#060724
Mysteriously and temporarily a hard drive shifts its
contents by 16 bytes.
PCIOdiscsperipheralshttp://WWW.sabi.co.UK/Notes/anno06-3rd.html#060724Mon, 24 Jul 2006 21:10:00 +0100Now IO has priorities too under Linux
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060723#060723
Just been told that the 'cfq' elevator under Linux can
prioritize IO, which can help with interactive responsiveness.
LinuxIOlatencyperformancegameshttp://WWW.sabi.co.UK/Notes/anno06-3rd.html#060723Sun, 23 Jul 2006 23:40:00 +0100Switched to SMP and voluntary preemption
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060713#060713
After a long time, my default Linux kernel build is now
for SMP and voluntary preemption, even if I have a
single CPU, just to improve interactive responsiveness.
I have switched because the popularity of dual core
chips means that the SMP and premption code is now an
itch for more people, so probably it is more reliable
than in the past.
LinuxSMPgameslatencypreemptionperformancehttp://WWW.sabi.co.UK/Notes/anno06-3rd.html#060713Thu, 13 Jul 2006 20:10:00 +0100Fixed front/rear ALSA parametric devices
http://WWW.sabi.co.UK/Cfg/ALSA/asound.conf?060704
Oops, just realized that the definition of the
front/rear split parametric PCMs was not quite right,
and cleaned it up too.
LinuxsoundALSAasound.confhttp://www.sabi.co.uk/Cfg/ALSA/asound.conf?060704Tue, 04 Jul 2006 22:45:00 +0100The 'ext4' file system and RHEL
http://WWW.sabi.co.UK/blog/anno06-3rd.html?060702#060702
There is now a plan to add 48 bit block addresses and
extents to the 'ext3' file system, and that sounds odd
as there are several other existing file systems with
the same or better features. But RedHat has a large
interest in extending 'ext3' rather than using a new
file system type for RHEL.
Linuxfile systemext3ext4JFSXFSReiser4RedHatRHELhttp://www.sabi.co.uk/Notes/anno06-3rd.html#060702Sun, 02 Jul 2006 23:00:00 +0100Updates list of file system description papers
http://WWW.sabi.co.UK/Notes/linuxFS.html#fsRefsDesc?060702
Added a couple of memos on the evolution of the 'ext3'
file system into the new 'ext4' one.
Linuxfile systemext3ext4RedHathttp://www.sabi.co.uk/Notes/linuxFS.html#fsRefsDesc?060702Sun, 02 Jul 2006 22:55:00 +0100Swap space misallocation in Linux
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060625#060625b
Linux allocates swap space blocks a bit too late, and
this causes severe performance problems. There is a
simple and general alternative.
Linuxvirtual memoryswappingpagingfile systemhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060625bSun, 25 Jun 2006 22:30:00 +0100Partial specialization for APIs in C++
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060625#060625
If an interface depends on more than one implementation
type C++ does not help a lot with avoiding code or API
duplication, because of a specific restriction.
C++templateclassinterfaceimplementationobject orientedhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060625Sun, 25 Jun 2006 21:35:00 +0100Sausages: 93% pork, but perhaps 55% pork meat
http://WWW.sabi.co.UK/Notes/miscShopping#msBritishSausages
A review of MS "british premium pork sausages", whose
ingredients include 93% "pork", but have perhaps 50% content of
apparently no nutritional value, and the protein content that
may imply perhaps only 55% pork meat overall.
shoppingporksausagehttp://www.sabi.co.uk/Notes/miscShopping#msBritishSausagesThu, 15 Jun 2006 23:25:00 +0100Sustainable ADSL traffic
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060612#060612
The results of some tests on the sustainable uplink and
downlink bandwidths for my ADSL line.
ADSLbandwidthnetworkingtraffic shapinghttp://www.sabi.co.uk/Notes/anno06-2nd.html#060612Mon, 12 Jun 2006 20:10:00 +0100Small updates to my IP shaping script
http://WWW.sabi.co.UK/#sourcesSabishape?060608
I have fixed a couple of small improprieties; also
introduced a distinction in the traffic classes between
the ceiling bandwidth (same as total for all classes)
and target rate, whose sum total is now lower, not
higher than the total for their parent.
LinuxnetworkingNetfilteriptablesshellshapingIPconfigurationtraffic controlThu, 08 Jun 2006 18:30:00 +0100Constructor, destructors, C++ and terminology
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060606#060606b
What ''constructors'' should do in C++, what the terms
''object'', ''constructor'' and 'destructor'' mean in
C++ and in computer science, and what ''destructors''
should do in C++.
C++objectconstructordestructorclass instanceobject orientedhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060606bTue, 06 Jun 2006 23:00:00 +0100The new Microsoft ClearType oriented fonts
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060606#060606
Found some screenshots of the new Microsoft Vista fonts
which are ClearType oriented. They are nice, but the
fringing is bad and the hinting makes them look bad
without antialising.
MicrosoftfontsClearTypeantialiasinghttp://www.sabi.co.uk/Notes/anno06-2nd.html#060606Tue, 06 Jun 2006 18:35:00 +0100No to keyboards with black keys
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060604#060604
In review of 10 keyboards 9 had black keys with white
lettering. It looks cool but with time it becomes unreadable.
hardwarekeyboardergonomicshttp://www.sabi.co.uk/Notes/anno06-2nd.html#060604Sun, 04 Jun 2006 16:10:00 +0100Linux based PS3 as PC replacement
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060603#060603
I had speculated that Sony sees a PS/3 with Linux as a
PC replacement, not just a games console. Sony's head of
development has confirmed this quite clearly.
PS/3SonyMicrosoftmarketingvideogameshttp://www.sabi.co.uk/Notes/anno06-2nd.html#060603Sat, 03 Jun 2006 10:05:00 +0100C++ and separating interface from implementation
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060602#060602
How to separate interface from implementation in C++, in
particular when the data representation is different,
but the API is equivalent.
C++templatesinheritanceinterfaceimplementationhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060602Fri, 02 Jun 2006 23:10:00 +0100Updates to file system notes
http://WWW.sabi.co.UK/Notes/linuxFS.html?060602
Many updates to my page of notes on Linux file systems,
mostly copied from the tech blog with some updates.
Linuxfile systemext3JFSXFSReiserFShttp://www.sabi.co.uk/Notes/linuxFS.html?060602Fri, 02 Jun 2006 19:50:00 +0100Coarse parallelism and pipeline duplication
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060528#060528
Some more illustration of what coarse parallelism in
games could be like, for example for characters.
videogamesSonyPS3parallelismCellhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060528Sun, 28 May 2006 22:10:00 +0100Non-virtual destructors in C++
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060524#060524
During a discussion of non-virtual destructors in C++,
someone suggested that they can be used to indicate a
class should not be derived for. Possibly, but it goes
against the grain...
C++virtualJavafinalhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060524Wed, 24 May 2006 23:40:00 +0100Updates to KDE notes
http://WWW.sabi.co.UK/Notes/linuxKDE.html?060515
Some revision and extension of my KDE notes, in particular
added details on how to do some particular tasks.
KDEhintsXLinuxperformancehttp://www.sabi.co.uk/Notes/linuxKDE.html?060515Mon, 15 May 2006 18:00:00 +0100Quick write speed test for CIFS and NFS
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060514#060514
A quick write speed test of CIFS and NFS, Linux-to-Linux
over a 100MHz network. Unexpectedly writing lots of
small files is slower with CIFS than NFS in asynchronous
mode. Either CIFS does not run in asynchronous mode or
perhaps lots more system calls is the problem.
Linuxfile systemSMBNFSCIFSSambaEthernethttp://www.sabi.co.uk/Notes/anno06-2nd.html#060514Sun, 14 May 2006 19:25:00 +0100Quick read speed test for CIFS and NFS
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060513#060513
A quick read speed test of CIFS and NFS, Linux-to-Linux
over a 100MHz network. As expected usually CIFS is preferable.
Linuxfile systemSMBNFSCIFSSambaEthernethttp://www.sabi.co.uk/Notes/anno06-2nd.html#060513Sat, 13 May 2006 20:15:00 +0100What is OO and why it works
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060512#060512c
A reminder of what OO is about and why it works. it is a
program decomposition paradigm where each
programmingsoftware engineeringobject orientedmodulesoverloadinggenericityhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060512cFri, 12 May 2006 20:50:00 +0100Inlining at the call site
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060512#060512b
Many important optimisations like inlining should apply
not to the definition of functions or classes, but to
their instantiations.
programmingsoftware engineeringoptimizationinlininggenericsoverloadingtemplatesinheritancehttp://www.sabi.co.uk/Notes/anno06-2nd.html#060512bFri, 12 May 2006 19:00:00 +0100Open, close or manifest type systems, programs and libraries
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060512#060512
Type systems can be open, closed or manifest, and code
can belong to programs or libraries.
programmingtype systemssoftware engineeringoptimizationCC++http://www.sabi.co.uk/Notes/anno06-2nd.html#060512Fri, 12 May 2006 18:20:00 +0100PS3 Gran Turismo HD halfway demo
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060511#060511
Some comments on the importance of Gran Turismo as a
Playstation signature game, and coarse parallelism,
relating to reports of an incomplete demo of the PS3
demo for the game.
videogamesSonyPS3parallelismCellhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060511Thu, 11 May 2006 09:45:00 +0100Quick speed test for Reiser4
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060510#060510
A quick speed test of Reiser4, with JFS as a reference
point, on my root filesystem. Looks good, but seems to
delay writing out modified inodes for a long time.
Linuxfile systemJFSReiser4performancehttp://www.sabi.co.uk/Notes/anno06-2nd.html#060510Wed, 10 May 2006 13:55:00 +0100Added review of Primark basic clothes
http://WWW.sabi.co.UK/Notes/miscShopping.html#primarkClothes?060509
Primark sells basic clothes that are cheap and of
reasonable quality.
Shoppingclothespolo shirtsunderwearPrimarkhttp://www.sabi.co.uk/Notes/miscShopping.html#primarkClothes?060509Tue, 09 May 2006 17:45:00 +0100Summarizing the font situation
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060509#060509
A simpler summary of what to do to have nice fonts with
GNU/Linux, at least in X.
LinuxX11fontsFreeTypeType 1TrueTypehttp://WWW.sabi.co.UK/Notes/anno06-2nd.html#060509Tue, 09 May 2006 16:50:00 +0100A nice working IT8212F chipset card
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060507#060507
Accidentally obtained a second IT8212F based ATA host
adapter, and this one actually works fairly well.
LinuxkerneldriverATASCSIRAIDhttp://WWW.sabi.co.UK/Notes/anno06-2nd.html#060507Sun, 05 May 2006 19:20:00 +0100Using SSL with name based websites
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060505#060505b
Usually it is believed that there only be one SSL
enabled web site per IP address, but there are at least
two important and useful special cases where there can
be multiple ones.
encryptionSSLHTTPwebApacheSSLOpenSSLweb servervirtual hostshttp://www.sabi.co.uk/Notes/anno06-1st.html#060505bFri, 05 May 2006 22:50:00 +0100Two papers on costs of garbage collection and reference counts
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060505#060505
Comments on two interesting papers on the space costs of
delayed reference counting, and the time cost of tracing
and delayed deallocation in garbage collection.
garbage collectionreference countingmemorymemory managementhttp://www.sabi.co.uk/Notes/anno06-1st.html#060505Fri, 05 May 2006 21:05:00 +0100Zalman Fanmate2 review
http://WWW.sabi.co.UK/Notes/hwNotesReviews.html#zalmanFanmate2?060505
A positive review of the Zalman Fanmate2 fan RPM
adjuster. It does not become hot.
hardwarecoolingnoisehttp://www.sabi.co.uk/Notes/hwNotesReviews.html#zalmanFanmate2?060505Fri, 05 May 2006 16:35:00 +0100Turning down fan RPMs for a quieter PC
http://WWW.sabi.co.UK/blog/anno06-1st.html?060504#060504
Thanks to a convenient Zalman Fanmate2 I have reduced
the speed of both my PCU and rear case fans to the point
I can't hear them anymore, and without much if any
increase in temperatures.
hardwarecoolingnoiseAthlonhttp://www.sabi.co.uk/Notes/anno06-1st.html#060504Thu, 04 May 2006 20:20:00 +0100Halo for PC and what is a CPU bound games
http://WWW.sabi.co.UK/blog/anno06-1st.html?060502#060502c
Halo for is a lot faster on my new CPU than the slower
one. Clearly CPU bound. Was this intentional?
videogamesperformancehttp://www.sabi.co.uk/Notes/anno06-1st.html#060502cTue, 02 May 2006 23:10:00 +0100Updates to the ALSA sound notes and configuration
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060502#060502b
Updates the the Linux ALSA sound notes and sample ALSA
lib configurations.
LinuxsoundALSAhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060502bTue, 02 May 2006 18:20:00 +0100Discoveries about FontConfig configuration files
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060502#060502
LinuxX11fontsFontConfighttp://WWW.sabi.co.UK/Notes/anno06-2nd.html#060502Tue, 02 May 2006 15:50:00 +0100Sample FontConfig configuration files
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060430#060430
LinuxX11fontsFontConfighttp://WWW.sabi.co.UK/Notes/anno06-2nd.html#060430Sun, 30 Apr 2006 22:40:00 +0100Fixed ALSA parametric devices
http://WWW.sabi.co.UK/Cfg/ALSA/asound.conf?060430
There was a bizarre but fatal problem in my parametric
'asound.conf' in the 'pcm.rec'/'dsnoop' configuration.
It is fixed now. Also, small updates and cleanups.
LinuxsoundALSAasound.confhttp://www.sabi.co.uk/Cfg/ALSA/asound.conf?060430Sun, 30 Apr 2006 22:10:00 +0100Updates to X11 sample config files
http://WWW.sabi.co.UK/Cfg/X11/?060430
Added DejaVu aliases.
LinuxX11fontshttp://WWW.sabi.co.UK/Cfg/X11/?060420Sun, 30 Apr 2006 21:30:00 +0100Freetype2 font rendering and quality
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060429#060429
The Linux fonts mess: what are the best options for
rasterization quality? Options and comparisons.
LinuxfontsTrueTypeType1X11FontConfighttp://www.sabi.co.uk/Notes/anno06-2nd.html#060429Sat, 29 Apr 2006 20:05:00 +0100When did the UNIX style start to fade?
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060424#060424c
The UNIX style of pragmatics is ever more forgotten...
When did the fade begin? I suspect that was with
SystemIII and 'fsck'.
LinuxUNIXpragmaticsstylehttp://www.sabi.co.uk/Notes/anno06-2nd.html#060424cMon, 24 Apr 2006 23:50:00 +0100Summary of fsck times
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060424#060424b
Gathering some 'fsck' times for two rather different
filesystems, and observations: time mostly proportional
to number of inodes, can be pretty long for large
filesystems, even in the best case.
Linuxfile systemext3JFSXFSReiserFSfsckperformancehttp://www.sabi.co.uk/Notes/anno06-2nd.html#060424bMon, 24 Apr 2006 23:40:00 +0100Some larger filesystem informal speed tests
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060424#060424
Some speed tests on a filesystem with 65GiB and 85k
files in it, under 'ext3', JFS, XFS, ReiserFS.
Linuxext3file systemJFSXFSReiserFSperformancehttp://www.sabi.co.uk/Notes/anno06-2nd.html#060424Mon, 24 Apr 2006 23:10:00 +0100Distasteful Microsoft bashing
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060423#060423
I have been sad to read a series of quotes bashing
Microsoft when they both are instead healthy self
criticism and they bash technical and project management
issues that are problems with free software too. Free
software is about freedom.
GNUmicrosoftfree softwareopensourcehttp://www.sabi.co.uk/Notes/anno06-2nd.html#060423Sun, 23 Apr 2006 19:55:00 +0100Disc-to-disc defragmenting and backups
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060422#060422b
Defragmentation is often best done by disc-to-disc backup
(image) and restore (tree). But then backup should be
done that way too.
Linuxbackupperformancefragmentationhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060422bSat, 22 Apr 2006 23:50:00 +0100Another file system speed test
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060422#060422
Some comments on what seems to me a rather flawed and
incomplete speed test of a few file systems. Still a lot
better than the previous one I had seen.
Linuxfile systemJFSXFSReiserFSext3performancefragmentationhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060422Sat, 22 Apr 2006 13:15:00 +0100Updates to Linux font notes
http://WWW.sabi.co.UK/Notes/linuxFonts.html?060420
Updates to my Linux font notes, with some extensions.
LinuxfontsTrueTypeType1X windowshttp://www.sabi.co.uk/Notes/linuxFonts.html?060420Thu, 20 Apr 2006 21:20:00 +0100Updates to Linux coding pragmatics
http://WWW.sabi.co.UK/Notes/linuxPragmaCoding.html#pathsDir
Added to the Linux coding pragmatics recommendations to
open files, especially configuration files, following a
directory path, and what the default path should look like.
UNIXLinuxprogrammingpragmaticshttp://www.sabi.co.uk/Notes/hwNotesReviews.html#pathsDirThu, 20 Apr 2006 14:00:00 +0100Online non-MMORPG game usage statistics
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060419#060419
GameSpy have a page with usage statistics for many
popular non-MMORPG online games. Well, they aren't so
popular compared to MMORPGs, except for CounterStrike.
gamesMMORPGhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060419Wed, 19 Apr 2006 23:40:00 +0100Some speed/compatibility tests of USB2/FW chipsets
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060418#060418
I have recently bought a new USB2/FW PCI card, and
somewhat earlier a new 3.5" external USB2/FW enclosure,
so I now have two of each; so i tested the various
combinations for compatibility and speed. The results
are as usual a bit depressing.
LinuxhardwareUSB2IEEE1394http://www.sabi.co.uk/Notes/anno06-2nd.html#060418Tue, 18 Apr 2006 21:15:00 +0100No Name ULT31311 review
http://WWW.sabi.co.UK/Notes/hwNotesReviews.html#nonameULT31311
Review of an ULT31311 external USB2/FW box for 3.5"
drives. It has some significant issues, and overall I can
tolerate it, but I wish I had bought another one.
hardwareUSB2IEEE1394http://www.sabi.co.uk/Notes/hwNotesReviews.html#nonameULT31311Tue, 18 Apr 2006 20:05:00 +0100No Name TT-346U2F review
http://WWW.sabi.co.UK/Notes/hwNotesReviews.html#nonameTT346U2F
Review of a TT-346U2F external USB2/FW box for 5.25" and
3.5" drives. It has some issues, but I like it.
hardwareUSB2IEEE1394http://www.sabi.co.uk/Notes/hwNotesReviews.html#nonameTT346U2FTue, 18 Apr 2006 19:15:00 +0100Solid, HAL, D-BUS, sysfs
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060416#060416b
Solid is the new KDE hardware abstraction layer, and is
build on top of various other already hairy layers. Not
the UNIX way, more like the Microsoft/Debian way.
Linuxhardwareautoconfigurationhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060416bSun, 16 Apr 2006 20:40:00 +0100Retesting JFS performance over time
http://WWW.sabi.co.UK/blog/anno06-2nd.html?060416#060416
More testing of JFS performance drop over time as
files get rewritten, this time after a full upgrade from
Fedora 4 to Fedora 5.
JFSfile systemLinuxperformancefragmentationhttp://www.sabi.co.uk/Notes/anno06-2nd.html#060416Sun, 16 Apr 2006 14:15:00 +0100Idiotic automagic in Fedora 5
http://WWW.sabi.co.UK/blog/anno06-1st.html?060327#060327
The script that start 'xfs' in Fedora 5 overwrites font
configuration files, and wrongly too.
Fedoraautoconfigurationfontshttp://www.sabi.co.uk/Notes/anno06-1st.html#060327Thu, 27 Mar 2006 20:15:00 +0000Impressive IO speedup on upgrading the CPU
http://WWW.sabi.co.UK/blog/anno06-1st.html?060326#060326
Upgrading my CPU and motherboard to significantly
faster ones results in massive improvement to the speed
of reading from hard drives under Linux, it looks like
IO under Linux is CPU bound, amazingly.
LinuxIOAthlon 64speedhttp://www.sabi.co.uk/Notes/anno06-1st.html#060326Wed, 26 Mar 2006 22:05:00 +0000Upgrading to Fedora 5
http://WWW.sabi.co.UK/blog/anno06-1st.html?060325#060325
After several months of using Fedora 4 I have upgraded
to Fedora 5. Overall I am satisfied, even if I have
disabled some of the more deleterious hacks.
LinuxFedorahttp://www.sabi.co.uk/Notes/anno06-1st.html#060325Tue, 25 Mar 2006 21:55:00 +0000Linux written page flushing can be fixed
http://WWW.sabi.co.UK/blog/anno06-1st.html?060323#060323
Just discovered that someone has found why modified file
pages can take a long time to be written back to disc
under Linux, irrespetive of the relevant kernel
parameters, and has produced a very useful patch.
LinuxIObufferinghard dischttp://www.sabi.co.uk/Notes/anno06-1st.html#060323Thu, 23 Mar 2006 19:20:00 +0000Test of recent PC games: CPU or GPU bound?
http://WWW.sabi.co.UK/blog/anno06-1st.html?060322#060322
A test of recent PC games as to when they become CPU
bound. The outcome is that a fast CPU is a good idea...
videogameshttp://www.sabi.co.uk/Notes/anno06-1st.html#060322Wed, 22 Mar 2006 23:50:00 +0000FT article on Godfather videogame
http://WWW.sabi.co.UK/blog/anno06-1st.html?060320#060320
The Financial Times writes about the impending release
of the Godfather videogame, whose delayed release cost
EA US$800m in its market value.
videogameshttp://www.sabi.co.uk/Notes/anno06-1st.html#060320Mon, 20 Mar 2006 16:30:00 +0000Small addition to Netfilter shell script
http://WWW.sabi.co.UK/#sourcesSabifire?060320
To make it easier for new users to understand the
firewall building script I have added two new options
to print 'iptables' commands before they are executed
and to not execute them.
LinuxnetworkingNetfilteriptablesshellfirewallIPIPv6configurationMon, 20 Mar 2006 16:05:00 +0000Added a firewall configuration script, reflections
http://WWW.sabi.co.UK/blog/anno06-1st.html?060319#060319c
After adding a shell script for firewall configuration,
reflections on how subtle and complex it is, and the
firewall configuration it generates too, and how users
mistakes physical accessibility of the sources and
distributions of free software with their accessibility
in a skills sense.
LinuxnetworkingNetfilteriptablesshellfirewallIPIPv6configurationhttp://www.sabi.co.uk/Notes/anno06-1st.html#060319cSun, 19 Mar 2006 23:50:00 +0000Shell script for creating IP/IPv6 Netfilter firewalls
http://WWW.sabi.co.UK/#sourcesSabifire
Just added a shell script to set up a leaf node firewall
configuration for Linux using Netfilter.
LinuxnetworkingNetfilteriptablesshellfirewallIPIPv6configurationSun, 19 Mar 2006 23:45:00 +0000The ClearSpeed architecture may interest AMD
http://WWW.sabi.co.UK/blog/anno06-1st.html?060319#060319b
AMD may be interested in using a ClearSpeed coprocessor
to enhance the floating point performance of its CPUs.
The ClearSpeed architecture presents some challenges.
CPUparallelismAMDhttp://www.sabi.co.uk/Notes/anno06-1st.html#060319bSun, 19 Mar 2006 22:50:00 +0000Cleaned the case filter, temperatures drop
http://WWW.sabi.co.UK/blog/anno06-1st.html?060319#060319
After cleaning the lower front filter for the air intake
of my PC case temperatures of the hard disks and the CPU
and chipset dropped significantly.
hardwarecoolingcasehttp://www.sabi.co.uk/Notes/anno06-1st.html#060319Sun, 19 Mar 2006 22:50:00 +0000Finally figured out ALSA parametric devices
http://WWW.sabi.co.UK/blog/anno06-1st.html?060315#060315b
The syntax for defining and making use of ALSA parametric
devices seems obscure, but I have eventually managed to
figure it out, at least in part.
LinuxsoundALSAasound.confhttp://www.sabi.co.uk/Notes/anno06-1st.html#060315bWed, 15 Mar 2006 23:55:00 +0000Usual not very useful error messages
http://WWW.sabi.co.UK/blog/anno06-1st.html?060315#060315
Classic example of not very useful messages because of
their incompleteness.
LinuxsoundALSAhttp://www.sabi.co.uk/Notes/anno06-1st.html#060315Wed, 15 Mar 2006 19:20:00 +000019" screens smaller than 17" ones, diagonals, ratios
http://WWW.sabi.co.UK/blog/anno06-1st.html?060314#060314c
A 19" inch widescreen monitor has less pixels than a 17"
one. Quoting monitor diagonals only makes much sense
if the aspect ratio is not much more oblong than the
classic 4x3 one.
hardwareLCDmonitorhttp://www.sabi.co.uk/Notes/anno06-1st.html#060314cTue, 14 Mar 2006 18:50:00 +0000Sort order, internet domain names, IP addresses
http://WWW.sabi.co.UK/blog/anno06-1st.html?060314#060314b
An important property in UNIX like systems is that data
be easily sortable. It is very annoying that internet
domain names and IP addresses in dotted quad notation
don't sort naturally.
UNIXpragmaticsprogramminghttp://www.sabi.co.uk/Notes/anno06-1st.html#060314bTue, 14 Mar 2006 17:50:00 +0000256MiB vs. 512MiB for top end videocards
http://WWW.sabi.co.UK/blog/anno06-1st.html?060314#060314
Nice test of two otherwise very similar top end
videocards, with 256MiB and 512MiB. At top quality
several modern games use way more than 256MiB of texture
memory. Indeed at lower resolutions and memory they use
more than 128MiB...
videocardsvideogamesNVIDIAhttp://www.sabi.co.uk/Notes/anno06-1st.html#060314Tue, 14 Mar 2006 17:35:00 +0000Measuring the CPU cost of shared libraries
http://WWW.sabi.co.UK/blog/anno06-1st.html?060313#060313
Someone has checked how much shared libraries cost in
CPU time. Not a lot in itself, but it adds up to a
significant overhead.
Linuxshared librariesELFhttp://www.sabi.co.uk/Notes/anno06-1st.html#060313Mon, 13 Mar 2006 20:20:00 +0000Ubuntu, the enterprise level distribution
http://WWW.sabi.co.UK/blog/anno06-1st.html?060312#060312d
Mark Shuttleworth proposes a delay in the next Ubuntu
release, and his reasons have to do with polishing it
into an enterprise level distribution
LinuxDebianUbuntuhttp://www.sabi.co.uk/Notes/anno06-1st.html#060312dSun, 12 Mar 2006 15:55:00 +0000Cell used in IBM blade servers
http://WWW.sabi.co.UK/blog/anno06-1st.html?060312#060312c
Using the Cell processor in IBM blade server, some not
so fresh news.
CellPS/3IBMSonyhttp://www.sabi.co.uk/Notes/anno06-1st.html#060312cSun, 12 Mar 2006 15:50:00 +0000Proof-of-concept virtual machine rootkits
http://WWW.sabi.co.UK/blog/anno06-1st.html?060312#060312b
Microsoft and UofM have crated some virtual machine
based rootkits as a proof of concept. Isn't DRM based
on VM technology similar?
Microsoftsecurityvirtual machineDRMhttp://www.sabi.co.uk/Notes/anno06-1st.html#060312bSun, 12 Mar 2006 15:35:00 +0000More on launch and pricing of the PS/3
http://WWW.sabi.co.UK/blog/anno06-1st.html?060312#060312
Comments on Sony's plans to deliver PS/3 before the end
of the year, on the meaning of 'spring' as a delivery
date, and Sony's hopes that in Europe those that
purchase Xbox 360 will also buy a PS/3, despite the high
prices of both.
Xbox 360PS/3DellSonyNintendoMicrosoftvideogameshttp://www.sabi.co.uk/Notes/anno06-1st.html#060312Sun, 12 Mar 2006 14:30:00 +0000Launch and pricing for PS/3, overlap with PC price range
http://WWW.sabi.co.UK/blog/anno06-1st.html?060309#060309b
Sony is sticking to its promise of a spring 2006 launch
for PS/3, and there is speculation on the launch price.
Probably PS/3 will be launched at the end of June 2006,
in very limited quantities, just the like Xbox 360, and
at a price, like the Xbox 360, which overlaps with the
price range of low end PCs.
Xbox 360PS/3DellSonyNintendoMicrosoftvideogameshttp://www.sabi.co.uk/Notes/anno06-1st.html#060309bThu, 09 Mar 2006 18:55:00 +0000The Nintendo Revolution is shrewdly designed
http://WWW.sabi.co.UK/blog/anno06-1st.html?060309#060309
The specification for the Nintendo Revolution are not
yet public, but it seems like that it will have fewer
processors and much more cache than PS/3 or Xbox 360,
and this will make it rather competitive.
RevolutionPS/3Xbox 360SonyNintendoMicrosoftvideogameshttp://www.sabi.co.uk/Notes/anno06-1st.html#060309Thu, 09 Mar 2006 17:35:00 +0000Retesting JFS performance over time
http://WWW.sabi.co.UK/blog/anno06-1st.html?060306#060306b
After two months of using my new fast 250GB discs I am
retesting how much performance in my root partition has
degraded. About twice, which is not too bad.
JFSfile systemLinuxperformancefragmentationhttp://www.sabi.co.uk/Notes/anno06-1st.html#060306bMon, 06 Mar 2006 20:05:00 +0000Intel is leaving HyperThreading behind
http://WWW.sabi.co.UK/blog/anno06-1st.html?060306#060306
Intel will stop doing hyperthreaded CPUs, as it is
switching to multiple cores. But recent game consoles
are still in effect HyperThreaded. Hard to exploit.
IntelHyperThreadingdual coregamesPS/3Xbox/360http://www.sabi.co.uk/Notes/anno06-1st.html#060306Mon, 06 Mar 2006 19:45:00 +0000Next generation game team sizes, one data point
http://WWW.sabi.co.UK/blog/anno06-1st.html?060305#060305
Lionhead are downsizing, and give numbers on how many
developers they retain for how many projects, giving
a rough indication of next gen team size.
videogamesPS/3Xbox/360http://www.sabi.co.uk/Notes/anno06-1st.html#060305Sun, 05 Mar 2006 14:15:00 +0000Source released for EECH, active community
http://WWW.sabi.co.UK/blog/anno06-1st.html?060226#060226c
Source has been released a while ago for the splendid
EECH games (Comanche Hokum and Apache Havoc), and a
still active community produces extension and mods.
videogamessimulationhttp://www.sabi.co.uk/Notes/anno06-1st.html#060226cSun, 26 Feb 2006 23:45:00 +0000Few online players for some popular games
http://WWW.sabi.co.UK/blog/anno06-1st.html?060226#060226b
There are really few online player for some popular
games. I guess that they are all playing WoW.
videogamesonlineMMORPGhttp://www.sabi.co.uk/Notes/anno06-1st.html#060226bSun, 26 Feb 2006 23:30:00 +0000KIAX keeps improving
http://WWW.sabi.co.UK/blog/anno06-1st.html?060226#060226
KIAX version 0.8.5 is more polished and useful. Too bad
ALSA support is still missing.
VoIPIAX2KIAXhttp://www.sabi.co.uk/Notes/anno06-1st.html#060226Sun, 26 Feb 2006 23:20:00 +0000Firefox caches a bit too much
http://WWW.sabi.co.UK/blog/anno06-1st.html?060219#060219b
Firefox gets mocked a bit for memory leaking, in
particular an intentional one, which however is misguided...
webbrowserMozillaFirefoxKonquerorhttp://www.sabi.co.uk/Notes/anno06-1st.html#060219bSun, 19 Feb 2006 21:50:00 +0000Reiser4 seminar at Google Talks
http://WWW.sabi.co.UK/blog/anno06-1st.html?060219#060219
Found an interesting video of a seminar about the design
the the Reiser4 file system, and the aim to escape
purely hierarchical or tabular arrangements.
file systemnamingLinuxhttp://www.sabi.co.uk/Notes/anno06-1st.html#060219Sun, 19 Feb 2006 17:10:00 +0000PS/3, GPU and software anti-aliasing
http://WWW.sabi.co.UK/blog/anno06-1st.html?060212#060212
An informal interview with a PS/3 developer reveals that
many PS/3 will not manage 1080p except via upscaling,
and that some people have been doing software anti-aliasing
on it, presumably using one or more SPEs.
PS/3videogamesparallelismCPUGPUgraphicshttp://www.sabi.co.uk/Notes/anno06-1st.html#060212Sun, 12 Feb 2006 22:30:00 +0000Updated KDE startup script
http://WWW.sabi.co.UK/#sourcesDokde
Updates and fixes to my version of the KDE startup script.
LinuxX11KDEconfigurationSun, 12 Feb 2006 21:55:00 +0100Intel on ELF linking optimisation
http://WWW.sabi.co.UK/blog/anno06-1st.html?060204#060204b
An Intel paper discusses ELF performance improvements,
and in particular the ''visibility'' issues, with some details.
ELFLinuxIntelhttp://www.sabi.co.uk/Notes/anno06-1st.html#060204bSat, 04 Feb 2006 15:45:00 +0000ECC RAM and recent motherboards with ECC
http://WWW.sabi.co.UK/blog/anno06-1st.html?060204#060204
Which motherboards do ECC given ECC RAM? Not many, and
here are some pointers by chipset and by model.
hardwareRAMmemoryECCmotherboardhttp://www.sabi.co.uk/Notes/anno06-1st.html#060204Sat, 04 Feb 2006 15:25:00 +0000Intel, Core Duo, and AMD price umbrella
http://WWW.sabi.co.UK/blog/anno06-1st.html?060203#060203
it is not clear why Apple switched to Intel, as the Core
Duo is a pretty good chip for laptops. It is also
interesting that Intel is playing low price alternative
to AMD's leading dual core chips.
hardwareAppleInteldual coreCPUhttp://www.sabi.co.uk/Notes/anno06-1st.html#060203Fri, 03 Feb 2006 22:30:00 +0000PS/3, ray tracing, Cell and NVIDIA
http://WWW.sabi.co.UK/blog/anno06-1st.html?060201#060201
Ray tracing is another possible use of those 7 SPEs in
a PS/3. Remembering the Transputer. And what about
in-game movies?
PS/3simulationvideogamesparallelismCPUGPUgraphicsray tracinghttp://www.sabi.co.uk/Notes/anno06-1st.html#060201Wed, 01 Feb 2006 22:50:00 +0000Reduced spin-up current options
http://WWW.sabi.co.UK/blog/anno06-1st.html?060130#060130
Just discovered that a manufacturer offers a reduced
spin-up current option for 2.5" drives meant to be used
in external USB/FW2 boxes.
hard discPSUhttp://www.sabi.co.uk/Notes/anno06-1st.html#060130Mon, 30 Jan 2006 22:20:00 +0000Lack of security is like lack of ECC for RAM
http://WWW.sabi.co.UK/blog/anno06-1st.html?060129#060129c
As a smart friend points out, lack of security measures
gives the same false sense of security as lack of ECC
for RAM.
securityauditingmemoryRAMECChttp://www.sabi.co.uk/Notes/anno06-1st.html#060129cSun, 29 Jan 2006 17:30:00 +0000Another reason why RAID5 is not a good idea
http://WWW.sabi.co.UK/blog/anno06-1st.html?060129#060129b
As a smart friend points out, RAID5 also implies a lot
more disk operations for the same amount of data, which
can mean a lot more wear and tear of the hard discs.
storagesystem administrationhttp://www.sabi.co.uk/Notes/anno06-1st.html#060129bSun, 29 Jan 2006 17:25:00 +0000WINE often faster than MS Windows
http://WWW.sabi.co.UK/blog/anno06-1st.html?060129#060129
Some benchmarks shows that WINE under GNU/Linux is often
as good or better than MS Windows at running WIN32 programs.
LinuxGNUWIN32WINEWINEOpenGLbenchmarkhttp://www.sabi.co.uk/Notes/anno06-1st.html#060129Sun, 29 Jan 2006 17:15:00 +0000Growth of MMORPG sales and decline of PC game sales
http://WWW.sabi.co.UK/blog/anno06-1st.html?060128#060128c
Looking at an impressive chart of the number of MMORPG
players over time suggests that the MMORPG industry is
taking a lot of customers and revenue from the PC game
industry.
gamesMMORPGPCsaleshttp://www.sabi.co.uk/Notes/anno06-1st.html#060128cSat, 28 Jan 2006 18:35:00 +0000Gran Turismo. PS/3 and partitioning by actor
http://WWW.sabi.co.UK/blog/anno06-1st.html?060128#060128b
Sony game consoles are probably designed for the benefit
of their signature games, primarily Grant Turismo, and
this may mean that the PS/3 is designed for partitioning
load by actor, not by global effect or game pipeline step.
gamesPS/3parallelismSMPhttp://www.sabi.co.uk/Notes/anno06-1st.html#060128bSat, 28 Jan 2006 17:50:00 +0000Games push PC technology, and why
http://WWW.sabi.co.UK/blog/anno06-1st.html?060128#060128
The driver of most upgrades to my PC has been increased
game requirements.
gamesGPUSMPtechnologyhttp://www.sabi.co.uk/Notes/anno06-1st.html#060128Sat, 28 Jan 2006 17:20:00 +0000RAID10 vs. RAID5, one data point
http://WWW.sabi.co.UK/blog/anno06-1st.html?060127#060127b
RAID10 is over 10 times faster than RAID5 for backups,
an even more dramatic difference than expected.RAID5RAID10diskbackuphttp://www.sabi.co.uk/Notes/anno06-1st.html#060127bFri, 27 Jan 2006 21:30:00 +0000Now I have 1GiB RAM, and yes it is much better
http://WWW.sabi.co.UK/blog/anno06-1st.html?060127#060127
I have sold out, or rather bought in 1GiB RAM, and
things are so much better than with 512MiB that it is
likely most kernel/KDE/GNOME developers have at least
1GiB themselves.
LinuxRAMECC1GiBswappingvirtual memoryKDEhttp://www.sabi.co.uk/Notes/anno06-1st.html#060127Fri, 27 Jan 2006 21:05:00 +0000Photo of the internals of a high speed 3.5" disc drive
http://WWW.sabi.co.UK/blog/anno06-1st.html?060113#060113
Found a nice photo of a high speed 3.5" disc drive which
shows it actually has 2.5" platters.
hard diskhard driveperformanceATAhttp://www.sabi.co.uk/Notes/anno06-1st.html#060113Sat, 13 Jan 2006 12:15:00 +0000Found extensive test of compression programs
http://WWW.sabi.co.UK/blog/anno06-1st.html?060111#060111
A friend has sent me a link to an extensive test of
compression programs, which includes decompression speed.
LinuxGNUcompressiondecompressionhttp://www.sabi.co.uk/Notes/anno06-1st.html#060111Wed, 11 Jan 2006 22:10:00 +0000Trends in game development
http://WWW.sabi.co.UK/blog/anno06-1st.html?060105#060105c
All games are becoming mods, and some games are
developed almost only to showcase a game engine which is
the real source of profits for the game studio
developing both game and engine.
gamesmarketinggame enginehttp://www.sabi.co.uk/Notes/anno06-1st.html#060105cFri, 05 Jan 2006 21:45:00 +0000Another interview with John Carmack
http://WWW.sabi.co.UK/blog/anno06-1st.html?060105#060105b
This interview is rather expansive and contains a
discussion of PC game piracy (with some dodgy arguments)
and on console development: if it looks like a PC it is good.
gamesmobile phonesXbox 360PS/3http://www.sabi.co.uk/Notes/anno06-1st.html#060105bFri, 05 Jan 2006 20:40:00 +0000Interview with John Carmack
http://WWW.sabi.co.UK/blog/anno06-1st.html?060105#060105
John Carmack comments on mobile phone games and toolkits
for them.
gamesmobile phonesDoomBREWJ2MEJavahttp://www.sabi.co.uk/Notes/anno06-1st.html#060105Fri, 05 Jan 2006 20:15:00 +0000Useful text mode/command line programs
http://WWW.sabi.co.UK/blog/anno06-1st.html?060102#060102
Found a page with a list of preferred command line
programs, so some comments and additions.
curseswebshellcommand linehttp://www.sabi.co.uk/Notes/anno06-1st.html#060102aMon, 02 Jan 2006 16:05:00 +0000The Linux registry, and other horrors
http://WWW.sabi.co.UK/blog/anno06-1st.html?060101#060101
When buyer fail to appreciate the importance of a
feature of a product, like maximum spin up current or
longest seek time, the feature stops being mentioned in
the specifications and then itself becomes worse. For
example this has happened to ECC support in motherboard
chipsets, which is a very important and nearly free feature.
hard driveperformanceECCRAMhttp://www.sabi.co.uk/Notes/anno06-1st.html#060101Sun, 01 Jan 2006 16:50:00 +0000Specifications become invisible and then the
feature fades too
http://WWW.sabi.co.UK/blog/anno06-1st.html?060101#060101
When buyer fail to appreciate the importance of a
feature of a product, like maximum spin up current or
longest seek time, the feature stops being mentioned in
the specifications and then itself becomes worse. For
example this has happened to ECC support in motherboard
chipsets, which is a very important and nearly free feature.
hard driveperformanceECCRAMhttp://www.sabi.co.uk/Notes/anno06-1st.html#060101aSun, 01 Jan 2006 15:15:00 +0000More on which hard drives to get for an upgrade
http://WWW.sabi.co.UK/blog/anno05-4th.html?051227#051227b
More thinking on the various conflicting requirements
for my upgrade main drive and its 3 backup drives. The
GHST and Maxtor drives match my requirements for both
internal and external drives, but I also want
diversification of manufacturer.
hard driveperformancestoragebackuphttp://www.sabi.co.uk/Notes/anno05-4th.html#051227bTue, 27 Dec 2005 18:20:00 +0000Poor swap speed with Linux
http://WWW.sabi.co.UK/blog/anno05-4th.html?051227#051227
It happens fairly often that my Linux desktop has to
swap in processes paged out because of memory pressure,
and this happens at 1MiB/s on a disc capable of 40MiB/s,
because of lots of arm movement. No relief in sight.
Linuxperformancevirtual memoryswappinghttp://www.sabi.co.uk/Notes/anno05-4th.html#051227Tue, 27 Dec 2005 18:00:00 +0000Using only the outer cylinders of a cheap disc
http://WWW.sabi.co.UK/blog/anno05-4th.html?051226#051226e
To enjoy fast disc performance one can buy a large
desktop disc and then use only its outer cylinders.
hard driveperformanceserverDBMShttp://www.sabi.co.uk/Notes/anno05-4th.html#051226eMon, 26 Dec 2005 23:50:00 +0000Recent PC games require top of the line systems
http://WWW.sabi.co.UK/blog/anno05-4th.html?051226#051226d
Having played some not so recently released FPS games on
my average PC they end up with low frame rates.
graphicsGPUgameFPShttp://www.sabi.co.uk/Notes/anno05-4th.html#051226dMon, 26 Dec 2005 23:25:00 +0000Power consumption of current hard drives
http://WWW.sabi.co.UK/blog/anno05-4th.html?051226#051226c
Hoping to upgrade my desktop PC to some larger discs, I
consider also spin-up power draw as some of those discs
will end up as backup discs in an external USB case. Only
a few models can do.
hard driveUSB2FirewirePSUhttp://www.sabi.co.uk/Notes/anno05-4th.html#051226cMon, 26 Dec 2005 22:50:00 +0000Latest numbers in over time filesystem slowdown
http://WWW.sabi.co.UK/blog/anno05-4th.html?051226#051226b
Four weeks ago I reinstalled from scratch my Linux root
partition, and I have been regularly upgrading it. How
much slower overall has it become? Only 1.8 times slower
with JFS.
filesystemFedoraspeedJFShttp://www.sabi.co.uk/Notes/anno05-4th.html#051226bMon, 26 Dec 2005 22:10:00 +0000Quake 4 performance on dual core systems
http://WWW.sabi.co.UK/blog/anno05-4th.html?051226#051226
Some comments on an interesting article as to
performance of a Quake 4 update that is multithreaded to
take advantage of hyperthreading or multiple CPUs, and
some comments on general strategies to achieve good speedups.
gameQuake 4hyperthreadingSMPIntelAMDhttp://www.sabi.co.uk/Notes/anno05-4th.html#051226Mon, 26 Dec 2005 22:05:00 +0000Using 'ext2' under MS Windows works well
http://WWW.sabi.co.UK/blog/anno05-4th.html?051219#051219
Having switched from FAT32 to 'ext2' the filesystems I
share between MS Windows and GNU Linux on my home PC a
few weeks ago, so far I am quite happy with it.
LinuxMS WindowsFAT32ext2http://www.sabi.co.uk/Notes/anno05-4th.html#051219Mon, 19 Dec 2005 22:05:00 +0000To optimize do not use expression oriented APIs
http://WWW.sabi.co.UK/blog/anno05-4th.html?051217#051217
When optimizing vector codes especially on CPUs with SIMD
oriented operations it is quite useful to avoid
expression oriented constructs like 'x = y + z', and just
use ''and becomes'' oriented APIs, like 'x = y; x += z'.
vectorarchitectureoptimizationhttp://www.sabi.co.uk/Notes/anno05-4th.html#051217Sat, 17 Dec 2005 17:15:00 +0000memory locality studies are not dead
http://WWW.sabi.co.UK/blog/anno05-4th.html?051216#051216
I have found a book that contains a number of mostly
well written essays on improving memory reference
locality. It is amazing that however little this is
practiced it is not yet a totally forgotten area.
optimizationarchitecturelocalitymemorycachehttp://www.sabi.co.uk/Notes/anno05-4th.html#051216Fri, 16 Dec 2005 22:10:00 +0000More stunning filesystem performance discoveries!
http://WWW.sabi.co.UK/blog/anno05-4th.html?051204#051204
Very interesting and unexpected performance issues with
filesystems, in particular 'ext3' with the 'dir_index'
option.
UNIXLinuxFedorafilesystemext3JFShttp://www.sabi.co.uk/Notes/anno05-4th.html#051204Sun, 04 Dec 2005 21:45:00 +0000Some decompression speed tests
http://WWW.sabi.co.UK/blog/anno05-4th.html?051203#051203
Comparison of 'bunzip2', 'gunzip' and 'lzop -d' as to
decompressing archives containing the same data.
UNIXLinuxlzopbunzip2gunzipcompressiondecompressionhttp://www.sabi.co.uk/Notes/anno05-4th.html#051203Sat, 03 Dec 2005 20:10:00 +0000KDE 3.5 has been released, Fedora 4 RPMs available
http://WWW.sabi.co.UK/blog/anno05-4th.html?051202#051202b
After the release of KDE 3.5, some Fedora 4 RPMs are now
available.
LinuxRedHatFedoraRPMKDEhttp://www.sabi.co.uk/Notes/anno05-4th.html#051202bFri, 02 Dec 2005 18:55:00 +0000Doom III with Voodoo 2 SLI, and bump mapping
http://WWW.sabi.co.UK/blog/anno05-4th.html?051202#051202
Some people have run Doom III on a Voodoo 2 SLI graphics
card, which does not have bump mapping. This makes clear
just how simple is the geometry in Doom III and how
effective bimp mapping at adding detail.
gamesDoom IIIgraphicsOpenGLhttp://www.sabi.co.uk/Notes/anno05-4th.html#051202Fri, 02 Dec 2005 17:50:00 +0000