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Message boards : Graphics cards (GPUs) : Mix and Match Video cards

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Profile Michael Goetz
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Message 8782 - Posted: 23 Apr 2009 | 12:48:00 UTC
Last modified: 23 Apr 2009 | 12:50:33 UTC

Um, I found this in one of Nvidia's CUDA manuals:


The use of multiple GPUs as CUDA devices by an application running on a multi-
GPU system is only guaranteed to work if these GPUs are of the same type.


That's from section 3.2 of this document.

It's not clear to me if that applies only to a single application attempting to use multiple GPUs, or if it applies to a BOINCish scenario where different applications are using multiple GPUs.

Mike

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Message 8885 - Posted: 25 Apr 2009 | 11:37:53 UTC

Someone posted that if you run foldinghome on mixed GPUs performance suffers, as if you had 2 of the slower cards. And that they supposedly also run seperate WUs on each GPU.

Regarding GPU-Grid I can only say that we don't seem to suffer such a penalty.

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Message 8906 - Posted: 25 Apr 2009 | 13:21:13 UTC - in response to Message 8782.

Um, I found this in one of Nvidia's CUDA manuals:


The use of multiple GPUs as CUDA devices by an application running on a multi-
GPU system is only guaranteed to work if these GPUs are of the same type.


That's from section 3.2 of this document.

It's not clear to me if that applies only to a single application attempting to use multiple GPUs, or if it applies to a BOINCish scenario where different applications are using multiple GPUs.

Mike


Well it works, sort of.

BOINC has issues in that it doesn't differentiate between the capability of the cards. We are having much discussion on the BOINC alpha email list at the moment how to best address this. Other than that it will run apps on the different cards without any issues other than BOINC scheduling (it runs the apps on the 1st card that becomes free) and estimates being wrong.
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Message 8999 - Posted: 27 Apr 2009 | 16:04:50 UTC

I can report that I have been running 3 cards (1 9500GT and 2 8800GTs) for the past 4 months. I have not encountered any issues with running GPUGrid.

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Message 9007 - Posted: 27 Apr 2009 | 19:11:27 UTC - in response to Message 8999.

I can report that I have been running 3 cards (1 9500GT and 2 8800GTs) for the past 4 months. I have not encountered any issues with running GPUGrid.

You will with the newest version 6.6.24 ... :)

We are trying to get a change to the decision to use a draconian test to select only the best and then identical cards to run ...

Actually, we are trying to get recognition that the halcyon days of symmetric computing resources is over and that BOINC needs to get smarter about how it schedules work ... sadly, it has been all up hill ...

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Message 9011 - Posted: 27 Apr 2009 | 20:28:15 UTC - in response to Message 9007.

I can report that I have been running 3 cards (1 9500GT and 2 8800GTs) for the past 4 months. I have not encountered any issues with running GPUGrid.

You will with the newest version 6.6.24 ... :)

We are trying to get a change to the decision to use a draconian test to select only the best and then identical cards to run ...

Actually, we are trying to get recognition that the halcyon days of symmetric computing resources is over and that BOINC needs to get smarter about how it schedules work ... sadly, it has been all up hill ...

Another reason I haven't upgraded to a newer version of BOINC past 6.5.0. Works fine for me, so I haven't made the leap to any new version.

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Message boards : Graphics cards (GPUs) : Mix and Match Video cards

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