Benchmark Results: Left 4 Dead
At 1680x1050, Left 4 Dead is entirely CPU-bound. Adding CrossFire or SLI only results in lower frame rates. We do get a great sense for how clock speed affects this game, though—at least between the three Core i5/i7 CPUs. The trio is favored, to be sure. And although the Core i5-750 features a more aggressive Turbo Boost implementation than the Core i7-920, it isn’t able to usurp the X58-based platform. Interesting also is that the ATI and Nvidia cards score identically. The bottleneck couldn’t get any more pronounced.
The competition opens up a little bit at 2560x1600. With a single Radeon HD 4870 X2 installed, AMD’s Phenom II X4 965 actually takes a first place finish, followed by the three Nehalem-based chips. With a GeForce GTX 285, all five platforms perform almost the same, notably slower than ATI’s flagship.
Drop in a second GeForce GTX 285, though, and Nvidia overtakes ATI, if only by a sliver. The Core i7-870, with its 2.93 GHz base clock, proves to be the fastest. Of course, even the lowest result in this chart is ridiculously quick. There’s no reason leave anti-aliasing and anisotropic filtering disabled in Left 4 Dead.
There’s a slight benefit to adding CrossFire or SLI at 1680x1050 with more visual detail applied, but certainly not enough to warrant buying a second graphics card. Again, the Core i7-870 takes a first place finish in this one.
At 2560x1600, with 4xAA and 8xAF enabled, all five platforms turn back the same results with a single Radeon HD 4870 X2 installed. The same happens when you sub-in a GeForce GTX 285, though the Nvidia card is quite a bit slower. Nvidia takes off with the addition of SLI though, sailing past a pair of Radeon HD 4870 X2s. ATI’s cards pick up performance too, but they don’t scale nearly as well.
Even though the cards on our P55-based platforms only get eight lanes of PCI Express connectivity each, the Core i5 and Core i7 systems still manage to out-perform the Core 2 Quad and Phenom II machines under the influences of CrossFire.