Call of Juarez: Bound in Blood
The Radeon HD 5870 does not show much dependence on the CPU in this game. The difference between the platforms is only noticeable at 1280x1024, but there is no point in choosing a faster CPU because the frame rate is already high enough. The CrossFireX tandem is clearly limited by the CPU.
This is the only test where the Intel Core i7 at 2.67GHz is the slowest CPU with the single graphics card. However, it goes ahead at the first step of overclocking. The single Radeon HD 5870 depends on the CPU until 1920x1200 at the high-quality settings. The two Radeon HD 5870 cards in CrossFireX mode respond eagerly to the overclocking of the three CPUs in every test mode and resolution.
Resident Evil 5
The third and the most resource-consuming scene of the benchmark integrated into Resident Evil 5 shows that the overclocked dual-core CPU is quite enough for a single Radeon HD 5870. And when you’ve got two such cards in CrossFireX mode, an Intel Core i7 920 at its default frequency will suffice.