you think can i get 3k cpm from 2 xgtx 680?
No. I think the performance should be around 2140 cpm with 2x GTX 680.
I just noticed that when running the 0.5 it puts a serious load on the cpu. Using a 1100T, I get all 6 cores at 93%-100% load.
Is there a setting to shift all the work to the gpu's?
EDIT: When running the 3b there is virtually no load on the cpu. I have one core that gets to maybe 25%.
Strange behavior, I don't know what happened currently on your system.
The CPU usage should be less than 1% on average even with GTX 660 and AMD Athlon 64 2650e CPU (15W TDP 65nm CPU).
All heavy work is done on GPU in all versions of PtsGPUz.
Thanks for the information you provided.