Message boards : Graphics cards (GPUs) : Different GPU on same Mobo?
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Does GPUGrid lose performance if video cards are mixed and matched? | |
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 K1atOdessaSend message Joined: 25 Feb 08 Posts: 249 Credit: 387,028,788 RAC: 1,197,795 Level  Scientific publications      | |
Does GPUGrid lose performance if video cards are mixed and matched? I run 2 880GT's and 1 9500GT together. The 8800GT's don't take a performance hit just because they are there with the 9500GT. They crunch at their own speed, and the 9500 crunches at its own speed. The 8800GT is for me about 3x faster than the 9500GT, so I get a result every 12-13 hours on the 8800GT and about every 40 hours on the 9500GT. I think that is consistent with other users, from what I have seen. | |
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ExtraTerrestrial Apes Volunteer moderator Volunteer tester  Send message Joined: 17 Aug 08 Posts: 2705 Credit: 1,311,122,549 RAC: 0 Level  Scientific publications | |
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At GPU-Grid every GPU crunches its own WU, without much external communication. Therefore you won't have a performance hit, what ever mixture you bring to the table. | |
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At GPU-Grid every GPU crunches its own WU, without much external communication. Therefore you won't have a performance hit, what ever mixture you bring to the table. I believe each GPU has its own work unit. I hear that the issue with using different cards (different shaders) is with the driver. For some reason, one card will take a huge performance hit if the shaders are different. This is only the case with Nvidia GPUs and not ATI so it must be driver related. Good to know this doesn't affect GPUGrid. | |
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i was going to ask the same thing. been looking for this topic type on google for awhile | |
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Up up. | |
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ExtraTerrestrial Apes Volunteer moderator Volunteer tester Send message Joined: 17 Aug 08 Posts: 2705 Credit: 1,311,122,549 RAC: 0 Level Scientific publications | |
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Been rethinking my answer: I think it's safe to say that we don't have anywhere near a 40 - 60% performance loss, as many people (e.g. Paul) have been running GPU mixes (also G92 and G200) and normally performance was fine. If there are a few % hit I don't know, neither if such a hit would be of the same magnitude if the cards were matched. | |
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Paul D. Buck Send message Joined: 9 Jun 08 Posts: 1050 Credit: 37,321,185 RAC: 0 Level  Scientific publications  | |
And there's this recent observation about tasks getting "stuck" with BOINC 6.6.20 and multiple GPUs. Could this be related? I am not sure. What I do know is that 6.6.23 is the latest drop and that is what I am trying on the i7 and since the project restart it seems to be running Ok... Of course it also has some GPU "Tweaks" in the code and I am not sure if they may have addressed the issue that was the source of the problem. | |
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Toby Broom Send message Joined: 11 Dec 08 Posts: 25 Credit: 431,137,443 RAC: 4,946,915 Level  Scientific publications | |
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Another thing to add is in the stat's where I have GTX260 and 8800GT, it say's I have 2x8800GT's | |
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Message boards : Graphics cards (GPUs) : Different GPU on same Mobo?
