cpu/gpu

[skyhifun]

I am so lost in what I read on Stanford website. Does the software use cpu cores or gpu cores or both? I keep seeing references to cores working alone and in support of a gpu. If one is not a total expert, does the software do these selections and let the smart boys tweak if they choose? I'm running an i7 5820K and a single gtx 970. A little explanation in simple English would be greatly appreciated.

[bruce]

Welcome to foldingforum.org, skyhifun.

While any documentation can be improved, it's very difficult to aim it at everybody, considering that FAH does a pretty good job of configuring itself so it doesn't need any tweaking. Consider the facts that the novices shouldn't need to tweak anything they don't understand and the experts need very little help. Nevertheless, you've come to the right place to ask questions and we're happy to provide answers to whatever you'd like to know.

FAH can run exclusively on the CPU (as far back as the first Pentium, or ever earlier, and up to the most powerful modern CPUs). In recent years, the ability to run on many GPUs was added, and those designed for use with modern games can do many times as much work as the CPUs could. Both can run concurrently, but the GPU needs one of the CPUs to pump data to/from it, so the default configuration reduces the number of CPUs dedicated to folding by one.

If you monitor FAH with the WebControl program, it provides a simplified view of what's going on, and the only performance setting that are available is the Power slider and the choice of whether to fold only when idle or while I'm working. For most people, that's all that's needed.

The Advanced Control program gives experts the ability to control ANY of the FAH settings and pretty much assumes you're a expert. Since there is no middle ground, we expect to get a lot of questions from those who are somewhere between Novice and Expert -- and we're happy to help.

If you have more questions or want a more detailed response, please provide the information requested immediately below.

[JimboPalmer]

The 5820K has 6 cores which can run a total of 12 threads. If you only configure the CPU it should use all 12 threads. If you also configure the GTX970, it should automatically reduce to 11 threads. Sometimes folding with a prime number like 11 fails, if so you can choose to use 10 threads in the Advanced configuration.
The GTX970 will need the latest driver direct from Nvidia. Very frequently the driver from the card vendor is not correct for Folding.

The CPU will work on one Work Unit, the GPU will work on an independent WU.

While not necessary, both your CPU and GPU will produce more Points Per Day if you use a Passkey.

[bruce]

Actually, there's no need to worry about the prime number 11. The FAHCore knows it's an unstable prime value and you'll see a message saying
:Mapping NT from 11 to 10