AMD 1090t Overclocked 4.1Ghz
8 gig DDR3 @ 1880
Gigabyte 5870 factory O/C to 950/1250
60 FPS solid with all settings max [ambient occlusion and depth of field off] Depth of field causes directX crash consistently 20-25 min in. Ambient occlusion, even with shadows and AA turned off, drops my FPS to 24 in the middle of nowhere. If not for the software mouse, it'd be playable.
i720QM @ 1.6 [turbo to 2.8]
Radeon 5870m 1GB DDR5
Slight mouse lag while playing, 4x AA shadows mid, ambient off, depth of field on. Very stable on this one, no idea why. 3600/2200ish on benchmarks.
AMD X2 9950 O/C'd to 3.0Ghz
8 gig DDR2
no shadows, no AA, standard/low
Mostly smooth, a little chop but May have been due to fragmented HDD. Slight mouse lag.
Benchmark. . hit 3000 low on the best day ever with as many tweaks as I could push on the thing. 2800 is probably about average. I don't remember high.