Is there any reason to not run cpu-heavy tasks (such as WCG) on a computer optimized for GPUGrid?

Any marginal performance improvement on gpu tasks?

2 nVidia 570's running with a 2G AMD 64 x2, 3800+ cpu

Ken Florian

If your two CPU cores are crunching other projects they won't have time to service the two GPUs which will leave your GPUs sitting idle. GPUs need a CPU to feed them data and collect the results of operations on the data on a nearly continuous basis.

There is a forum here titled Frequently Asked Questions. If you look at it you will probably find a thread that already answers your question as well as other questions new GPU crunchers frequently ask. I think your question about running other projects alongside GPUgrid is answered there.

Also in the Frequently Asked Questions section, there is a thread about which cards are recommended for this project and which are not. I think you'll find 9800s are not useful at this project and if you look at the results your two 9800s are returning you can see why they are not useful here.

I'll certainly review all the faq items. My question isn't about my single running gtx 550ti. It is about reconstituting a system, with to-be-purchased gpus and a psu, explicitly for gpugrid (and only gpugrid) tasks. Last week I disabled gpugrid tasks on all my cards except for th gtx550 per input from gpugrid.

Thank you for the help.

Ken Florian

I run Rosetta at home on all of my GPUGrid computers to make sure the CPUs and GPUs stay nice and hot! Rosetta at home is a CPU only project so it never attempts to use the GPUs at all.

Many posts warn not to run this type of configuration but with thousands of successful work units completed, it is safe to run both CPU and GPU intensive tasks on the same machine. Usually GPUGrid applications take priority when necessary over the Rosetta apps to keep data flowing to my GPUs.

The intel Q6600 systems (overclocked of course) will keep data flowing to a GTX 570 or a GTX 580. Never tried dual cards in these systems but I am looking for a GTX 590 and that should be about the same load as 2 GTX 570s.

Let us know how it goes.
____________
Thx - Paul

Note: Please don't use driver version 295 or 296! Recommended versions are 266 - 285.

The conventional wisdom is clear that running both CPU intensive and GPU intensive apps on the same computer should cause a decrease in performance.

With Rosetta at home, I have one CPU task for each core (this includes the virtual cores on hyperthreading CPUs like the Core i7). On a Q6600, I have 4 Rosetta processes + a GPU process. On a Core i7, there are 8 Rosetta processes running + 2 GPU tasks (2 GTX 570s).

My experience is that the GPU tasks take priority over the CPU tasks. If you look at my computers, projects and results, you should notice that all systems are overclocked and that my stats are a little better than expected on both CPU and GPU projects.

It would be good to know if others have similar or different results.
____________
Thx - Paul

Note: Please don't use driver version 295 or 296! Recommended versions are 266 - 285.

You're right. Theory and conjecture are fun to bandy about in a forum, the proof is in the results so we need an experiment along the lines of what ET Apes mentions. A representative set of WUs shouldn't be too difficult to obtain and averaging is not a problem, it's keeping all the other influences and factors constant while changing only the control variable(s). I mean when I think about the activity on my own crunch box it's mayhem, the only constant is that it's chaos. If you remove the chaos then it's not a real life test and then you're back to bandying about theory and conjecture concerning what the meaningful numbers actually mean. What to do?

OK, but how does one evaluate performance? How about recording % GPU utilization every minute or so for each task and when the task is done record the median % usage as one measure of performance. Another measure could be the run time. Are there any other data that might be useful? Obviously I'm talking about employing a script to collect the data and another to process/analyze it later.

I've got one machine with a GTX 550 ti.

The only thing it does is GPUGrid and, for now, WCG. It is not used for any other automated or human-generated computing purpose.

It complete a long run in about 30 hours.

I could accumulate a set with WCG running then pul WCG out of the mix for another same-sized set.

I would say go for it, kflorian, but I wonder if a same sized set is the best way to get meaningful data. There is only 1 science app in use at this project but there are several researchers submitting tasks and each type of task uses the GPU and CPU differently. The more experienced hands here can advise best but I think you/we have to make sure all types of tasks are represented equally in both sets. In other words, if the set with WCG has 10 type A, 20 type B and 16 type C tasks then the set without WCG should have the same numbers of each type of task.

I also think it might be informative if GPU usage percentage were recorded too. What I propose is far too much work to do manually so I propose a script that will gather the data for us and allow anyone who wants to use the script to accumulate data for hundreds of tasks with next to 0 effort. Once the data is recorded, stored and made available to whoever wants it, it can be analyzed at leisure any number of ways.

I can write the script to collect the data, probably in Python for ease of cross-platform compatibility, but I want to discuss what the script should do first and whether or not it's really needed.

In the meantime you can gather whatever data you want, of course, and I'm sure we'll all be interested in your report.

I run GPUGRID and Docking on my 1055T based system. Up until now I have used all 6 cores for crunching Docking. Today I have set docking to only use 5 cores to see what difference it will make to crunching times. The 6th core has been freed to service my GTX460 and GTX550Ti.

With GPUGrid and Rosetta running at the same time - Monitor GPU Utilization - 60 seconds.

Suspend Rosetta - all tasks - Monitor GPU Utilization - 60 seconds

After several iterations over 2 days - results - no increase in GPU utilization when Rosetta tasks are suspended. Testing on multiple computers with different size CPUs and GPUs.

This is not a scientific test but provides some interesting data points. Perhaps the GPUGrid tasks take higher priority than Rosetta. These two projects co-habitate well.


____________
Thx - Paul

Note: Please don't use driver version 295 or 296! Recommended versions are 266 - 285.

I was running a 285GTX on an old P4! CPU which was fully loaded including HT there was no problem with GPUGrid, only needed to free the CPU as FAX4 units came, because they used alot CPU Power parallel to get 24h bonus including the nearly 1hour upload ^^ So i would say the most times you can use the full cpu. But 570 are more powerful then the 285 (witch is not the slowest card too) so it could make a difference. But on my C2D 8400 @ 3,6Ghz and 560TI i can run Fax4 with CPU full loaded with not much difference.

Would say it could better to hold one core free when you want to get the maximum out of the older x2 CPU. On the other side, it seems FAX4 units are done and i can reactive CPU work now, so you can do it too :)
____________
DSKAG Austria Research Team: http://www.research.dskag.at



Crunching for my deceased Dog who had "good" Braincancer..