CPU Use Count Not Same as Logical CPUs

[BubbaJNelson]

CPU use count used is not same as Logical CPUs... I have a desktop with four cores and eight logical CPUs. LAH shows only seven logical CPUs in use. I have another desktop with two sockets, each with four cores and eight logical CPUs. LAH shows only 31 logical CPUs in use. Please explain. Thanks.

[BobWilliams757]

From my understanding, one logical CPU/thread will be used to feed the GPU on a system. I'm not completely sure if there is any way to resolve that, since even built in graphics need CPU resources to feed data to them.

[JimboPalmer]

Welcome to Folding@Home!

If you have a AMD or Nvidia GPU F@H will reserve 1 thread (F@H calls them CPUs) to feed the GPU with data. If you do not fold with your GPU, you can delete the GPU slot and use all the CPUs.

[jrweiss]

You should use the Configure tab on the FAHControl screen to reconfigure those to 6 and 30 logical CPUs, respectively. The F@H client does not work well with CPU counts that are Prime numbers.

Also, you might get better usage by limiting the dual-socket machine to 12 CPUs for each CPU Slot. There are often more Work Units available for the lower core count, and sometimes the client fails to assign a WU if it sees a large core count in the slot. Reduce the current slot to 12 CPUs. Then add 2 more slots, with 12 and 6 (or 8, if not Folding with the GPU) CPUs, respectively.

[BubbaJNelson]

Thanks. I am now running on all threads/CPUs/Slots.

[Neil-B]

A 32core should be kept busy 24/7 at the moment on advance flag and is better for the science and points than splitting up ... I have only once had the AS not have a WU for that slot and it dropped in a 12core WU instead and down cored the slot for that WU.