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I'll highlight the important bits:
At 1680x1050, all cards above the 5750 (6750) will have playable frame rates at full settings with 4x MSAA. Those with the GTS450/5750 would have to probably just drop AA to get playable frame rates.
At 1920x1200, you're looking at ~5830/6850/GTX460 1GB cards for full settings and a smooth frame rate.
At 2560x1600, a GTX560 Ti or 6950 and above cut the mustard at full settings.
Interestingly, even at full settings, the 1GB cards don't suffer from VRAM shortages, despite the memory hungry engine (seeing as the 6870 1GB somehow outperforms the GTX480 in this test).
Overall, it looks like AMD cards do slightly better than Nvidia cards, but it's all quite even.
They also tested triple monitor set-ups with the 6970, 6990 and GTX590.
At 5040x1050 (three 1680x1050 screens), all three cards produced playable frame rates, though the 6970 was a little low. The 6990 led the way.
At 5760x1200 (three 1920x1200 screens), the 6990 again won out, but the 6970 couldn't produce playable FPS.
At 7680x1600, we finally see a setup where drifting's wafflings about 1.5GB VRAM inadequacies actually show to be true, as the GTX590 collapses. Only took 5.3x the resolution to prove it.
They also did a CPU test, and Dirt 2 really likes:
-Cores (Phenom II X6 did very well)
-L3 Cache
This actually led to the i7 920, i5 750, Phenom II X6 1100T and Phenom II X4 980 all beating the 2600K and 2500K, but they were all close. Any Athlon-based CPU (or Phenom II X2) fell way behind.
I'll highlight the important bits:
At 1680x1050, all cards above the 5750 (6750) will have playable frame rates at full settings with 4x MSAA. Those with the GTS450/5750 would have to probably just drop AA to get playable frame rates.
At 1920x1200, you're looking at ~5830/6850/GTX460 1GB cards for full settings and a smooth frame rate.
At 2560x1600, a GTX560 Ti or 6950 and above cut the mustard at full settings.
Interestingly, even at full settings, the 1GB cards don't suffer from VRAM shortages, despite the memory hungry engine (seeing as the 6870 1GB somehow outperforms the GTX480 in this test).
Overall, it looks like AMD cards do slightly better than Nvidia cards, but it's all quite even.
They also tested triple monitor set-ups with the 6970, 6990 and GTX590.
At 5040x1050 (three 1680x1050 screens), all three cards produced playable frame rates, though the 6970 was a little low. The 6990 led the way.
At 5760x1200 (three 1920x1200 screens), the 6990 again won out, but the 6970 couldn't produce playable FPS.
At 7680x1600, we finally see a setup where drifting's wafflings about 1.5GB VRAM inadequacies actually show to be true, as the GTX590 collapses. Only took 5.3x the resolution to prove it.

They also did a CPU test, and Dirt 2 really likes:
-Cores (Phenom II X6 did very well)
-L3 Cache
This actually led to the i7 920, i5 750, Phenom II X6 1100T and Phenom II X4 980 all beating the 2600K and 2500K, but they were all close. Any Athlon-based CPU (or Phenom II X2) fell way behind.