I noticed that MilkyWay CUDA takes up almost a whole core as you can see in this image (the 'img' tag didn't work with windows-skydrive).

Anybody else that have seen this behaviour?

When another MilkyWay task runs on this system (it only runs the GPU tasks) I'll check it again too see if it's a recurring problem.

Anthony.

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The longer I live, the more reasons I develop for wanting to die.

It's a known recent Nvidia driver problem where OpenCL things take up huge amounts of CPU time for no reason.

If this is really a driver problem, do you know if Nvidia is working on it?
Or else would it be possible for MilkyWay to make different apps, 1 type for CUDA and 1 type for OpenCL?

Anthony.

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The longer I live, the more reasons I develop for wanting to die.

I'm having the exact same issue.

I disallow all my projects to use CPU time, as they have full use of my GPU. Yet as you mention above it has lead us to nvidia driver bug?

I'm on the latest 285.62 - Anyone seen or heard of any updates to this?

I noticed that it doesn't do this on every WU. But out of the 4 or 5 I checked it showed this behaviour on 3 or 4 WU's.

Anthony.

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The longer I live, the more reasons I develop for wanting to die.

280.13 shows this effect on all WU, taking 200% on 2 cores of my 2500k

I had the same problem with nvidia driver 280 and 285. CUDA takes at least one whole core (if the cpu idles CUDA even takes 2 cores).

There are no problems with driver 266.

I couldn't install driver 266 as it didn't support both my videocards (GF8600GT & GTX550Ti) so I tried driver 270.61 and that one seems to work too. No problems here yet after checking about 5 WU's.

Anthony.

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The longer I live, the more reasons I develop for wanting to die.

I just wrote a support request on NVIDIA's website about this problem and another problem I have (driver crashes when suspending Collatz on my GF-8600GT, that's also in my system together with my GTX-550Ti; my GTX-550Ti runs al other GPU projects I have).

Anthony.

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The longer I live, the more reasons I develop for wanting to die.

I had the same problem with nvidia driver 280 and 285. CUDA takes at least one whole core (if the cpu idles CUDA even takes 2 cores).

There are no problems with driver 266.

+1

Is there anything that could be changed in MW app to fix this?

I had the same problem with nvidia driver 280 and 285. CUDA takes at least one whole core (if the cpu idles CUDA even takes 2 cores).

There are no problems with driver 266.

+1

Is there anything that could be changed in MW app to fix this?

Not as long as it is a OpenCL app.

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I had the same problem with nvidia driver 280 and 285. CUDA takes at least one whole core (if the cpu idles CUDA even takes 2 cores).

There are no problems with driver 266.

+1

Is there anything that could be changed in MW app to fix this?

I'm pretty sure I can write a workaround for it.

That would be great :)

BTW, how much memory does a GPU WU take, because maybe I could run more than 1 WU on a 1GB GTX-550Ti. But then I'm gonna need an app_info.xml also for it. On SETI and Einstein I already run 3 WU's concurrently.

Thanks in advance for the rewriting.

Anthony.

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The longer I live, the more reasons I develop for wanting to die.

BTW, how much memory does a GPU WU take, because maybe I could run more than 1 WU on a 1GB GTX-550Ti.

It should take (mu * r * (number of streams + 1)) * (1 or 2) * sizeof(double) bytes. For a typical work unit this would be (1600 * 1400 * (3 + 1)) * 8 = 68MB.

So I would be able to run 14 WU's at once on my GPU, but would limit it to 10 just in case. Now to get an app_info.xml.

Anthony.

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The longer I live, the more reasons I develop for wanting to die.

You also have to take into account how much of a load 1 WU has on the GPU, if you are already around 80 to 90 percent, 2 at a time would be the max.

Otherwise you are slowing down all wu needlessly.

This will have the appropriate app_info to start.
http://www.arkayn.us/forum/index.php?action=downloads;sa=view;down=33

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It's possible to achieve a small benefit by running 2 WUs per GPU because there is a small pause in GPU usage each time a WU nears completion. If 2 WUs are run in tandem, then the second one will use all available GPU during this period. Running more than 2 at a time will yeid no additional benefit and has the potential to cause additional problems.

Is there anything that could be changed in MW app to fix this?

I'm pretty sure I can write a workaround for it.

Any news on the workaround?

Anthony.

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The longer I live, the more reasons I develop for wanting to die.

the GPU-apps could be much, much longer then only a few minutes.
it´s not good to share so short WU. that´s a heavy, heavy load for the server(s) even a lot of WU are returning in minute takting :/

please increase the calculation-time for 1a. ATI 1b. Nvidia up to 50x-100x and the servers and databases will be very stable and can do the work step-by-step without trouble ;)

Norman

I'm pretty sure I can write a workaround for it.

And I'm pretty sure you can do it. But... are you doing it?