Getting back into folding...

[Athlex]

Been a few years but with this cool weather, I thought I'd fire up F@H again and do something useful while keeping the room warm.

My system is relatively old (Phenom II X6 1090T 3.2GHz @ 3.8GHz) and from what I'm reading, CPU folding isn't really worth much at all compared with GPUs. Is it worth running the CPU at all on a couple cores or is it just a detriment to the GPUs? It's funny looking through team stats since I'm ranked 55th in points and 4th in WU from the horde of [mostly P4] machines I used to fold with...

GPU-wise, I have a pair of identical Sapphire R9-280 boards in an AMD 970 (x16 and x4) crossfire setup. Looks like PCIe bandwidth is definitely a bottleneck since I'm getting ~18,000 PPD from one board, and ~33500 PPD from the other.

Couple questions for the pros here-

• Does enabling/disabling Crossfire matter? Output seems to float between 40,000 and 44,000 PPD with or without crossfile with both GPUs running and the CPU paused, so I'm guessing "no?"
  
• I'm reading good things about Windows 10 versus Win 7 for folding. I'm currently on Win 8.1, any idea if I'd see an improvement if I were to upgrade?
• Any other suggestions for getting the most out of this setup? Efficiency-wise, it seems like running the faster GPU is ideal, but also wondering what other things I'm not considering like the value of WUs from different projects.
• Edit: Any benefit to disabling programs like f.lux while Folding?

Thanks for any tips!

 

[StefanR5R]

Regarding PCIe bandwidth: GPU-Z and HWiNFO64 are showing a "bus interface load" percentage (with Nvidia 10-series GPUs at least) which I presume is utilization of the PCIe bus. With my comparably fast cards (GTX 1070, 1080), this bus interface load during typical F@H WUs is shown at about 33 % for PCIe 3.0 x16 and somewhat less than 50 % for PCIe 3.0 x8. So, extrapolating from PCIe 3.0 to PCIe 2.0, x16 and x8 should still be fine, but PCIe 2.0 x4 is likely to be a bottleneck at least for similar Nvidia cards.

Also, from the thread "Getting the most PPD out of your hardware for F@H":

Regarding the PCIe bus, I have personally found that maximum performance requires PCIe v2.0 @8x or better. Performance drops off sharply at 4x, and nearly dies at 1x.

This information from Mark and myself has been proven on GTX 1080, 1070, 980, and 980Ti cards.

Your numbers indicate that the same is true with AMD R9 cards.

(The "Getting the most PPD..." thread has a lot more info of this kind.)

 

[Markfw]

I am slightly confused on ppd. My R9 290 was doing about 220,000 ppd for ONE card. Is the 280 that much slower ?

I don't know about crossfire, but SLI is supposed to work, but does create problems.

 

[Athlex]

I am slightly confused on ppd. My R9 290 was doing about 220,000 ppd for ONE card. Is the 280 that much slower ?

Good grief, that's a huge difference. With both GPUs and CPU running, I'm consistently in the 55,000PPD range. From what I'm seeing, the R9 280 is basically 2012-era silicon since that drive the 79x0, 8950, and R9 280, so I guess it's just that old.

I've also been experimenting with Crossfire enabled and disabled over the last day or two and I'm not seeing any significant difference, so I guess it's not as temperamental as SLI.