Combination of Low Watt CPU/GPU

[LikZ]

How would it perform to combine something like this:

http://www.asrock.com/mb/AMD/QC5000-ITX ... dex.de.asp

with a more powerful GPU like a GTX970/980? The PCI Slot works with x4 which should be fine. Project 9201 needs some CPU Power but e.g a i5 Ivy is only stressed to about 25% for that. Anyone working with something like this?

[bruce]

I'm confused, Did you give the wrong link? The link you gave is to a A4, not an i5, and the PCIe is x16, not 4x as you suggest. Neither one of those factors would have a major influence on the answer. Something like either one would be fine to drive a GTX 9x0 (as long as you consider the power supply and the cooling).

The BIOS may or may not allow you to enable both GPUs at the same time. The integrated HD 8330 is fine to drive a screen but would be too limited for FAH. Folding on it is not recommended. (I have one, and it doesn't meet the deadlines.) Either the A4 or the i5 could use 75% to fold for a few added PPD, but that, too, is a minor consideration.

[LikZ]

No the Link was right. The i5 was just for Comparison. An actual working i5 takes 25% Power when the 970 is working on a 9201 project. So i was wondering if the A4 would perform well enough. The Pcie Slot is a Pcie x16(4x) Slot. Thats why i wrote 4x

[davidcoton]

The 25% should be one core flat out in a loop, waiting to service the GPU. The actual work needed from the CPU is small, if not negligible. A less powerful CPU should be fine.

[bruce]

The 25% should be one core flat out in a loop, waiting to service the GPU. The actual work needed from the CPU is small, if not negligible. A less powerful CPU should be fine.

Whether the CPU core runs flat-out or just uses a small percentage depends on the way the drivers are designed. The flat-out design maximizes GPU performance at the expense of CPU activity whereas GPU performance is reduced somewhat when the CPU is allowed to go to a wait-state. (Ask any gamer...or the GPU salesman... how important they consider the frame-rate to be.)

This is one time where HyperThreading (or AMD's equivalent) is a distinct win for FAH since "half" a CPU doesn't steal resources that CPU Folding cares about from the other half.