CPU Scaling and Performance
To measure the kind of impact CPU overclocking might have on DNF's performance, we shifted the Core i7 920 from 2.0GHz and 3.8GHz. We also installed a GTX 580 to eliminate GPU bottlenecks. We recorded 28% speed boost when jumping from 2.0GHz to 3.8GHz, suggesting that DNF does place a fair bit of load on the CPU.
We found that DNF utilized four cores and will max out the fastest dual-core processor. That said, clock speed does seem to be the key factor here, as the Phenom II X2 560 was just a fraction slower than the equally clocked six-core Phenom II X6 1100T processor.
When testing the Athlon II X4 645 it became apparent that the L3 cache also plays a huge role. However, even the slowest processor tested, being the Athlon II X2 265, was still capable of powering the GTX 580 to 87fps.
Clocked at 3.7GHz, the Phenom II X4 980 was able to match the Core i7 920, but the new i5 2500K and i7 2600K were a little faster.