Is it possible to see a decrease in video performance when overclocking the cores from 2.8ghz to approx 3.0ghz? My temps are fine. Without the overclock on the cpu my BFG GTX 260 Core 216 scores (650 core/1100 mem) scores an 1890 in passmark, but with the CPU overclocked the passmark score drops to 1765. Can anyone explain this? What am I better off doing other than the obvious upgrades?