Computer Speeds Surprising....
1 Sep 2011 12:55:14 UTC
Topic 195931
(moderation:
I have two of my machines running both GPU and CPU WUs. Both of them are running the same OS and both have the same driver versions. One is an i5 2500k CPU with a GTX460 at stock clocks. The other machine is an i7 with a GTX470 with a factory overclock. The i7 has hyper-threading while the i5 does not. Shockingly to me the i5 machine with the slower graphics card seems to be doing more work than the other machine. Both have only been running 3 or 4 days but the i5 average credit is 5920 and the i7 average credit is 2640.
Does this make any sense?
Computer Speeds Surprising....
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The i7 has almost twice as many pending tasks as the i5. So, the RAC is not the best means to compare the two.
However, the i7 has a higher turnaround time with less downlaoded tasks. (Downclocking/heat?)
Gruß,
Gundolf
Computer sind nicht alles im Leben. (Kleiner Scherz)
The temperatures appear to be
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The temperatures appear to be ok. As for downclocking I am not sure what would cause that.
Here are a few notes that I
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Here are a few notes that I can think of:
1) If you have the 920 loaded 100% with 8 CPU work units, this will slow down the GPU work units. The use of hyperthreading has some affect over GPU performance. I would suggest keeping the CPU load below 50% or disable HT and keep the CPU load below 75%. I also use Process Lasso and set the GPU application to higher priority and bind the application to the non-HT cores. There are options for both in this program.
2) The 2500k has an integrated PCI-E controller whereas the 920 has the PCI-E controller integrated via the x58 chipset. In the case of the x58, the data from the GPU has to pass through the IOH and then via a QPI link to the CPU. With the 2500k, the GPU is directly connected to the CPUs PCI-E controller so there is likely a bit less latency from the GPU to CPU.
3) Higher CPU frequency does significantly help GPU performance. If you have the proper cooling, you might look into increasing the frequency a bit.
Thank you for the info. In
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Thank you for the info. In Windows process viewer all 8 cores are fully loaded. I will try tweaking down the usage and see if that helps.
I'm running an I7 with an
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I'm running an I7 with an GTX460, using 5 of the 8 GPU's with a load of 80% plus in parallel two GPU tasks (using an app_infp.xml file).
I get an RAC on this machine of ~18.000 credits. It's a little bit less at that time, cause of the slow BRP4 work generators, which don't give me 24 hours continous workload. Currently I'm crunching 14.000 credits/day with that machine
The 2500k machine is also
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The 2500k machine is also loading all four cores at 100% so I am surprised that isn't slowing it down.
Hi You can use the "local"
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Hi
You can use the "local" preferences settings in BOINC manager to tell BOINC to use only a certain percentage of the cores ( say 6/8 or 7/8) on that machine. Anyway you 470 seems to underperform, and I would check if the Gfx card is a) recognized as a PCIe 16x device and b) running on full clock rate. There is a known problem when BOINC switches tasks between GPU projects that can cause the card to fall into a power save mode without switching back to performance mode. A fix should be ready soon.
PS if you check your results you will see that a few days ago the 470 returned GPU tasks in less than half the time it does now, so I suspect it's currently indeed running on reduced clock rate)
HB
I looked back and found those
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I looked back and found those faster ones too. Very interesting. Surprisingly though even they are slightly slower than the 460 results. I would think that my 470 would blow that 460 away with the extra memory and extra cores.
Is there an easy way to reset the clocks?
RE: Is there an easy way to
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Reboot the computer.
If I were on your position, I
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If I were on your position, I would switch the gpus. The 2500K is more powerful and can feed the 470 with enough data. You can use a tool like the msi afterburner to watch gpu utilisation and see the difference.
If I deactivate HT on my i7 2600K, the gtx460 in my machine runs at >85% with one work unit and up to 95% when running 2 work units at the same time.