Few things to note:
- DX10 is not the reason I advocate the 8800 GTS, although future proofing is nice
- There is a company putting together a DX10 stand-in library for XP, and it should be ready well before games start coming out in force with DX10.
Scores for the three cards from Tom's Hardware:
1280x1024x32, 4x AA, 8x AF
HDR/SM3.0:
- 8800 GTS 320MB = 2505
- X1950 Pro 256MB = 1349
- 8600 GTS 256MB = 1238
SM2.0:
- 8800 GTS 320MB = 2732
- 8600 GTS 256MB = 1632
- X1950 Pro 256MB = 1502
1920x1200x32, 4x AA, 8x AF HDR/SM3.0:
- 8800 GTS 320MB = 1505
- X1950 Pro 256MB = 763
- 8600 GTS 256MB = 634
SM2.0
- 8800 GTS 320MB = 2062
- X1950 Pro 256MB = 974
- 8600 GTS 256MB = 650
In all but one scenario the 8800 GTS scores about as well as the other two cards combined.
Last benchmark I will show has to be explained a bit. In a lot of games they cap the FPS rate. So Composite FPS scores can be a bit missleading, better cards generally lose a lot of ground on the lower settings as they are throttled back to a point where they are identical to the other cards. Most people will be trying to play on the highest resolution their card can reliably handle so it can be a bit misleading imo.
In this case the FPS scores are from BattleField 2142, Dark Messiah, Doom 3, MS Flight Simulator X, Oblivion, Prey, and Warhammer: Mark of Chaos. They try the games at a wide variety of settings and add all of the scores together to get the following result....
Composite FPS:
- 8800 GTS 320MB = 1827.8
- X1950 Pro 256MB = 1243.8
- 8600 GTS 256MB = 1127.5
Ben, let me know if you are considering any other cards and I can add them to this list. Ultimately its best for you just to get an idea of how they perform and then you can make a choice based on whats best for your needs.