Shutdown for Earth Hour

To mark this years Earth Hour, all the machines at the office (including the servers) have been shut down for the weekend. The only machine crunching at the moment will be shut down for the hour at 20:30 tonight.
Running older hardware does often worry me in terms of the credit/watt rating I achieve, but I guess it is still more productive than all that hardware out there that sits idle while chewing countless kilowatts.

BOINC client update through Synaptic on Ubuntu

The version of BOINC that is included in the Ubuntu default repositories is rather outdated. I used the deb file from www.getdeb.net to install a client (6.4.5) that was recent enough to allow me to run a CUDA card on my 64-bit Ubuntu installation. I am the kind of person who will never remember to check for updates, so I have added getdeb.net to the repositories so that Update Manager and Synaptic can see updated packages.
This is achieved by adding "deb http://ubuntu.org.ua/ getdeb/" to the Third Party sources in Software Sources (found in System > Administration > Software Sources). This will also update a number of other packages on your computer, so make sure you are happy with the security and version numbers before you go ahead.

SETI for CUDA on Linux vs Windows

Well, the question posed last week regarding the big difference in performance between my CUDA card under 64-bit Ubuntu and cards under Windows has been answered.
I finally spotted an instance where two 8600GT cards have received the same work unit. The machine (AMD 64 X2 6000+) running 64-bit Windows finished the work unit in 156.45 seconds while my machine (AMD 64 X2 4200+) running 64-bit Ubuntu finished in 2968.83 seconds. That is a difference of 94.37%!
Looking at the CPU bench-marks, the Ubuntu machine is actually quicker so that shouldn't influence the result. The only notable issue is that the Windows machine has double the memory, both RAM AND GPU memory.
It will be interesting to see if this major difference still exists when SETI release their own Linux client...


After some time searching forums for ideas, the following two concepts were suggested by a user on the lunatics.kwsn.net forums:

1. 256M of GPU memory is right on the border and this may cause the work unit to fall back to CPU computation. I'm not convinced about this as I have watched the GPU temperature and there is no evidence that it stops crunching.
2. The linux CUDA application does use 100% of a core and I was just thinking that the "0.04 CPUs" line was a complete joke. The time reported could well reflect the "wall time" for the work unit, Windows on the other hand does use a small percentage of a CPU core (I believe..?), so the time reported to complete a work unit isn't necessarily anywhere close to "wall time". If this is the case, a Windows machine essentially has another core compared to the Linux machine and will have a higher credit average ...Grrrr!