Hahah, wow. Installed my single new 4870 last night (going to grab another cheapie in a months time perhaps as I did with my 2900's - that solution actually worked perfectly), and performance is truly amazing. I mean, with all the shit you read about the game and how performance hogging it is, I honestly expected very little of it, but man was I susprised. I started by firing up the game and increasing my settings (to the best of my recollection) to;
Graphics Settings
Video Mode: 1280 x 1024 (100 Hz)
Texture Quality: Medium
Render Quality: Medium
Reflection Resolution: Medium
Water Quality: Medium
Shadow Quality: Medium
View Distance: 20
Detail Distance: 20
Definition: On (this one is retarded, turning it on turns the blur effects and such OFF, but I can still just hit P to get them back, and vice versa)
VSync: Off
On those settings, the game was... Unimaginably smooth (coming from the old x1900). I haven't actually benchmarked yet, got too caught up in playing, but even with a full batallion of police after me in cars, swat vans and helicopters, flying down a crowded street dropping molotovs and blowing shit up left right and centre, it felt smooooooth. In the absence of a framerate counter, I'm going to say MINIMUM 40fps at all times. It never once got visibly or (feel, uh, feelably?) chunky or bogged down. And believe me, I would spot it, I'm beyond anal about framerates, 100 is my sweet sweet nectar.
So after that experience, I went with these settings;
Graphics Settings
Video Mode: 1280 x 1024 (100 Hz)
Texture Quality: Medium
Render Quality: Very High
Reflection Resolution: High
Water Quality: Medium (staying with this because after playing I checked out that comparison on water quality and Medium is sexiest)
Shadow Quality: Very High (Patch 1.0.2.0 has fucked shadows, the higher the better)
View Distance: 35
Detail Distance: 30
Definition: On
VSync: Off
And it's STILL just as smooth as before. Colour (color, huuurr) me impressed, I'm having a lot of rucking fun with this card. I guess it really helps to have this Q6600 purring along at 3.4+ghz.