Benchmark: DiRT 2
DiRT 2, a lovely-looking racer and one of the first games to use a DX11 path offers improved visuals whilst burning through the London map.
Silky-smooth frame rates in DiRT 2, and we'd expect nothing less from £1,000+ GPUs.
There's little to choose between the two cards in terms of raw throughput, so the buying decision may rest on power consumption, temperature and noise.