Folding on your GPU - Does PCI-E Speed matter?

Big.Wayne

Big.Wayne

Big.Wayne

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Does anyone know if PCI-E speed effects production rate?

I am thinking that it doesn't due to most of the crunching takes place locally on the graphics card without a lot of data travelling up and down the PCI-E lanes?

I'm considering adding a second card (non primary) for folding and the motherboard I am using defaults to PCI-E 2.0 x8 on both slots . . . . I am aware this doesn't impact gaming performance too much so along that train of thought it seems reasonable too assume it will make no noticeable different to PPD :confused:

Any feedback appreciated :)
 
dont think so, pci-express is an insanly fast system anyway and has a massive theoretical bandwidth because of its parrallel lanes (the x1 , x4, x8, x16 speeds)

Per lane bandwidths are:

v1.x: 250 MB/s
v2.0: 500 MB/s

multiply this by the adress lanes being used and you get BIG numbers (never actually achieved but nm)

So although the difference between 8 lane speeds and 16 lane speeds is a factor of 2, this is a difference betwwen a max bandwidth of 8 and 4 GB/s - this obviously wont be anywhere near utilised in either setup.
 
x8 lanes are fine for F@H. Im pretty sure that a 4x lane is considered fine for F@H as well, but its not something i have tried. I think its when you get down to 1x/2x that the GPU would becme limited by the speed of the lane, but certainly running a couple of cards on x8 lanes is fine. :)
 
one of my cards is running at 4x. Identical points per day (ppd) to 16x. Apparently you can go down to 2x with only a tiny hit on ppd.
 
Had no issues running the Asus with 4 slots, two were x8 and two were x4 I think when it was all loaded up
 
K thanks all for replies, I guess even at PCI-E 2.0 x4 there is enough bandwidth to keep the GPU crunching, at least on nVidia cards but not so sure about ATI as they do seem to use a lot of CPU?

Anyway got the answers I was hoping for so thanks again! :)
 
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