When equipped with the HD 7970 GHz Edition, raising the Core i7-3770K's clock rate 80% from 2.5GHz to 4.5GHz only produced a 10fps (15%) performance increase, suggesting that Core i7 and likely Core i5 owners needn't worry about overclocking to get the most out of their graphics card in Far Cry 3, as the rewards are minimal.
When testing with the AMD FX-8350, we saw nearly a 60% performance increase when jumping from 2.5GHz to 4.5GHz, so folks with AMD CPUs will likely want to overclock as much as they can for max performance. It's interesting to note that the FX-8350 at 4.5GHz was only able to match the Core i7-3770K at 3.5GHz.
Like most of today's games, Far Cry 3 can use four cores or threads, so it's no surprise that dual-core chips suffer, as evidenced by the Phenom II X2 and Athlon II X2. However, core/thread efficiency is also extremely important and this is where the Intel has an edge, with the i7-3770K and i7-3960X topping our chart.
Below those two juggernauts was the Core i5-3470 with 65fps, followed by the FX-8350 at 64fps. The old Core i7-920 showed that it still has plenty of fight left with 60fps, outdoing most of the AMD parts, while the dual-core (quad-thread) Core i3-3220 averaged 55fps, allowing it to match the much higher clocked FX-4170.