Thread: Imagine the PPD
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Old September 9, 2009, 04:29 PM
Zero82z Zero82z is offline
Join Date: Sep 2009
Location: Montreal, QC
Posts: 5,415

My System Specs


Originally Posted by bissa View Post
EDIT: what does affect how well a GPU can fold?
Number of shaders, shader speed, and overall GPU architecture.
Originally Posted by Sushi Warrior View Post
The new Classified 4x SLI mobo with 7 GTX295's with waterblocks and single slot brackets? Or does the mobo not support that many GPU's? Rather have 7 295's over another processor.
There is a limit to how many GPUs you can use in a system altogether. See below for more info.
Originally Posted by El_Fiendo View Post
I think there is a limit of 4 GPUs. I'm not sure if this is Windows or Forceware drivers (or even a hardware issue). It's not an SLI issue (as in SLI will work up to x4 but you can have more graphics cards un-SLI'd), I think more along the lines of actual GPU recognition past 4 of them. I'm probably wrong though. Anyways, I've never seen anyone run 4 GTX 295s without at least 1 core giving them an issue, so I'd personally stick to GTX 285s.
Based on experiments from other users with regards to large multi-GPU setups, this seems to be the conclusion: there is a fundamental limit in Windows that permits only up to eight display outputs. That means that you can use no more than four dual-GPU cards in one system, and even four single-GPU cards would use up that number. Furthermore, Windows Vista sees cards like the GTX295 and 9800GX2 as having three outputs per card due to the separate HDMI port in addition to the two DVI outputs, so that ends up limiting Vista machines to 5 GPUs (the first two dual-GPU cards count as 6 outputs, and one of the GPUs of the third dual-GPU card counts as two outputs). XP doesn't have that problem, so you can fold on up to 8 GPUs under that OS. However, you can't use any more than that.
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