GPU Problem

Chris
Chris
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Is anyone else running a GTX

Is anyone else running a GTX 650? Not the Ti.

The switch to BRP5 has slowed trying to figure this out. At one point, I had 16,000 rac (brp4) and now I'm down to 13,000 (although I was up to 15,000 at one point a week or so ago.)

Running 2 BRP5 at a time they're taking anywhere from 44,000 seconds to 60,000.

Still seeing a sawtooth pattern on the gpu load. That seems unusual too.

Gary Roberts
Gary Roberts
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RE: Is anyone else running

Quote:
Is anyone else running a GTX 650? Not the Ti.


I'm running both - but mostly the GTX650. All hosts have a single GPU only.

On BRP4, I got the best performance by running 2x. Performance seemed to suffer a bit when I tried (very briefly) 3x. There was no significant performance drop with running tasks on ALL CPU cores. Over quite a few hosts, both dual core and quad core, both PCIe2 and PCIe1.x (as long as the host had DDR3 RAM), a GTX650 could complete 2 tasks in 59-62 minutes, which gave a theoretical RAC of ~23K from the GPU alone. All these hosts had actual RACs of between ~24K and ~28K, depending on the CPU contribution. The actual motherboard (perhaps the precise chipset configuration) could make quite a difference. Boards supporting DDR2 RAM only, always seemed to perform quite poorly for me.

All these hosts are now running BRP5 and I'm progressively trying them out 3x (3 tasks in parallel - only on 650Ti and 550Ti so far) even though the GPUs are all 1GB. I'm still loading all CPU cores with CPU tasks and there seems to be a small further gain over 2x in the cases I've tried. I'm taking things slowly but there is a real gain and (for me) no adverse consequences (yet). Of course, I'm not doing anything (much) but crunch on these hosts.

It's quite expected to have a significant drop in RAC for quite a while after the transition to a new run like this. Lots of hosts have teething problems so it takes a while for things to settle and for 'pending' results to ultimately be confirmed. If you look through tasks lists on hosts, you can see quite large numbers of 'pending' results and 'resend' tasks (suffix greater than _1) and this is a good indication that RAC will be dropping. You can expect a RAC 'bonus' soon when these 'pendings' start being finalised at a rate greater than new ones are being created. That has already started for me and my RAC has increased by ~10% in the last few days.

I just checked one of my hosts with a GTX650 and a Sandy Bridge Pentium dual core CPU in an el cheapo H61 (PCIe2) motherboard. It is doing BRP5 tasks 2x in 30ksecs (very consistently) which is much faster than the values you have quoted. The thing holding you back is probably your motherboard/chipset/RAM although I can't really say as I have no experience with your Phenom II 840 so it might be that. Is your RAM DDR2 or DDR3?

Cheers,
Gary.

Chris
Chris
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I started this thread with a

I started this thread with a major slowdown on BRP4 tasks. Its not just BRP5, its just making it harder to measure. I had 2x BRP4 tasks go from 1 hour and 15 minutes to 2 hours.

8gb of ram, ddr3.

Gamboleer
Gamboleer
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Hi Chris, I've never

Hi Chris,

I've never encountered it with my 650, but I sometimes had a problem with an ATI 5770 (running on a Mac) in which the completion times would mysteriously slow down. Shutting the system down completely (not a simple reboot, and sometimes it took 2-3 tries) seemed to fix the problem.

Alec

Chris
Chris
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I went down to 1x tasks to

I went down to 1x tasks to try and minimize any feeding issues from the motherboard or ram. Running with a free core too.

Its doing 30-35k seconds for a single task.

I'll shut it down, check my connections, blow out the dust, and then see what happens.

TJ
TJ
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I have seen this too on an

I have seen this too on an Albert@home WU. With a clean (dust free system).
Bit other use 71% load so could be a WU problem.

Try to run a GPU WU only so leave all CPU cores free, see what happens.
Secondly try another project, to see what the GPU load is then. Milkyway@home has short WU's you can check but the GTX650 has to have double precision. Or try a short run task from the magnificent GPUGRID project. That is a good test case, but takes you at least 6 hours to complete.

Greetings from
TJ

Chris
Chris
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Looks like my PSU fan isn't

Looks like my PSU fan isn't turning.

GPUZ looks fine, but speedfan had a heart attack. I think I will need to solve that problem first.

MAGIC Quantum Mechanic
MAGIC Quantum M...
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RE: Looks like my PSU fan

Quote:

Looks like my PSU fan isn't turning.

GPUZ looks fine, but speedfan had a heart attack. I think I will need to solve that problem first.

Oh my!

Well you probably know that is one thing that can never fail since a CPU is hot even when the fan is running and will soon fail.

Fans are cheap and CPU's are not.

I lost one years ago (amd 1600) it booted up while I was gone so when I came home it went to my pc parts pile.

I tend to check the CPU-Z and GPU-Z and the EVGA PRECISION X since I OC

Good luck Chris

Chris
Chris
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Credit: 45,056,670
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Power supply does seem to be

Power supply does seem to be spinning now. Can't really tell if its working at full speed. It had no play in the bearings or grittiness though when I had it out.

Backed off all the CPU tasks. I am now seeing a constant GPU load, but we'll see what the final times are in a few hours.

Downloading evga precision x now, because my computer actually runs hotter when I don't run any cpu taks. Case fans are pretty inadequate on this one and I cant control the cpu fan.

Chris
Chris
Joined: 9 Apr 12
Posts: 61
Credit: 45,056,670
RAC: 0

I can run 0 or 1 cpu task and

I can run 0 or 1 cpu task and have a level gpu load. Running a second cpu task gets me a smaller downgrade in speed.

Even with 2 tasks and the GPU load, I'm under 75% processor load, so it seems like the bottle neck experimentally, but I can't see the reason for it in my head.

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