Call of Duty 5: World at War
Call of Duty 5: World at War responds to the increased speed of the platform, too. The efficiency of CrossFireX depends on the CPU as well as the platform at large. There is almost no performance growth on the weak Intel Core 2 Duo. The results are higher on the faster quad-core AMD Phenom II X4 but it is only with the Core i7 that the Radeon HD 5870 pair shows its best at 1920x1200 with high-quality settings. From a practical point of view, the speed of 80fps delivered by the single Radeon HD 5870 with Intel Core 2 Duo at 2.67GHz is already quite enough. Unfortunately, I could not measure the bottom frame rate, which might be the guiding factor for choosing the lowest allowable CPU for playing Call of Duty 5: World at War comfortably.
Left 4 Dead
Left 4 Dead is not a resource-consuming game, either (and I’m planning to replace it with Left 4 Dead 2 in my future reviews), so it is hard to see that some CPU is insufficient for a Radeon HD 5870 or a CrossFireX tandem of two such cards. We can see that there is little difference between the CPUs with the single Radeon HD 5870 in the 8x MSAA + 16x AF mode at 1920x1200 whereas the CrossFireX tandem speeds up only on the Intel Core i7 platform. The lack of bottom speed data reduced the practical value of these numbers, though.
Warhammer 40 000: Dawn of War II
CrossFireX technology is not supported by Warhammer 40 000: Dawn of War II and the results get only worse when you turn it on. However, the results of the single graphics card are quite indicative of the performance of the platforms and the influence of the CPU because this game proves to be quite demanding in this respect. Overclocking each platform helps increase the average and bottom frame rates. Unfortunately, the quad-core AMD Phenom II X4 loses even to the Intel Core 2 Duo, let alone the Intel Core i7. The latter delivers an impressive increase in bottom speed, which is most necessary for comfortable play.