What game? Have you enabled dualcore in "configure"? Also you should get a newer Rev, I'm not quite sure but I seem to remember the 36xx revs being crappy.
Specs: intel i5 3570k @ 3.4GHz;
16Gb RAM; Raedon HD 7900;
Win8 64-Bit
16Gb RAM; Raedon HD 7900;
Win8 64-Bit
