Forum > GPU crunching
V10/11 of modified SETI MB CUDA + opt AP package for full multi-GPU+CPU use
Kashra:
Hey,
have you tried to run one project solo? You can turn off AP in your Boinc main account settings in setiathome.de
perhaps the AP code is messing around with the Seti apps especially since you have a i7 920 cpu with the "hyperthreading" feature. Could really be a bottleneck caused by I/O from AP or seti running together. Just try to run seti alone and recheck your times, if they are fine you got your solution - use the cc_config file to limit Seti+AP e.g. to 9 or 10 procs including the GPUs to have 1 or 2 CPU cores left for system and kernel stuff.
codeman05:
I was thinking it could be a I/O issue as well.
How exactly do I limit the number of active CPU's in the cc_config.
Is it still the: <ncpus>6</ncpus> for example?
UPDATE:
I just dropped the Processor Utilization in the BOINC pref's to 50%, so now I have 4 AP's running and 3 CUDAs......CUDA WU time dropped from 17min to 10 mins...
I think you were right.
I guess the real question then is, is the "loss" of 4 AP units worth the 25-50% decrease in CUDA WU times.
Raistmer:
--- Quote from: codeman05 on 16 Apr 2009, 09:26:22 pm ---I just dropped the Processor Utilization in the BOINC pref's to 50%, so now I have 4 AP's running and 3 CUDAs......CUDA WU time dropped from 17min to 10 mins...
--- End quote ---
Very interesting.
I did some standalone benchmarking of CUDA MB while CPU running 4 another BOINC tasks (not AP though, einstein@home ones) and didn't see any degradation in CUDA MB elapsed times and speed.
But it was quad w/o HT.
Do you use V10 or V11 CUDA MB build from this thread or stock one?
Raistmer:
--- Quote from: codeman05 on 16 Apr 2009, 09:26:22 pm ---
I guess the real question then is, is the "loss" of 4 AP units worth the 25-50% decrease in CUDA WU times.
--- End quote ---
Well, if forget about fact that 1 sec of AP work gives better credit than 1 sec of SETI MB work it seems you didn't change total host performance.
There were reports that with HT on 8 AP took twice the time 4 AP take with HT off on the same host. You leaved HT on but affectively disable some on CPU cores.
Try to compute overall host work done in both your configs (unfortunately, credits not very suitable for that cause AP and MB credit rates different).
Raistmer:
New VLAR limit value used (0.12 instead of 0.14). For details see this thread:
http://lunatics.kwsn.net/12-gpu-crunching/gpu-cpu-pefrmance-dependence-from-ar-value.msg16800.html#msg16800
[attachment deleted by admin]
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version