CPU and GPU at once?

[LIGISTX]

So I have started folding on my parents i3 while I am home (will let it go once I am back at school as well, FOR SCIENCE!) But my question is, I will have two different rigs to fold on, an aging 775 machine with a e6600 @ stock (Can't push it, I pencil moded the mobo and it "died" on me once, long story short, it works now but I don't want to go out of spec with it), a 2500 (not a K so can't really OC), a GTX 275 and a GTX 460. I plan to use all of these, but my experience in the past was that folding 100% on CPU and GPU significant slows down the CPU PPD which is fine, I just want to make sure my GPU's are being maximized  as I assume they will put out more numbers than the CPU's.

 

Question is, should I run a GPU on each machine and leave say 1 core open on each CPU to be dedicated to handling the GPU folding, or run both GPU's on the 2500 system? I just want to maximize the help I am giving to the cause!

[FireFox]

Question is, should I run a GPU on each machine and leave say 1 core open on each CPU to be dedicated to handling the GPU folding, or run both GPU's on the 2500 system? I just want to maximize the help I am giving to the cause!

 

If you want to but if you set the slider to light it uses 50% of the CPU (on mine at least) so should give you a decent amount left over for other things, the PC's will have to be on idle though for the GPU is kick in unless you set it to full usage (I really don't like that, come on F@H).

[Whaler_99]

With the new Core17 project - CPU utilization hit from the GPU is a lot better, but you are not always guaranteed to get one. When you get a Core16 - bam.

 

So yes, a good idea is to leave one core free. So on a 4 core system for example, only have CPU:3.

 

As for the video cards, totally up to you if you want to run both GPU in one or split them. Won't make much difference if you have both systems up and running and folding on the CPU...