1920x1200 & Racing Sims - 8800GTS 640Mb or 8800GTX?

[[H]eatpipe]

I'm getting a Dell 2407WFP-HC to run on a separate gaming system.
The system has aged a bit, but it's still perfectly usable.
AMD FX-60
2Gb Corsair XMS
EVGA 7900GTX
FSP 700W PS

The only games that I play are GTR2 and Rfactor racing simulations.
Both run on the same DX9 engine and supposedly are not very shader-intensive.

On the current monitor, at 1600x1200, I have to slightly limit the visuals for performance,
but night-races bog the system down quite a bit due to headlights, etc.
Night + rain gets really slow.

That makes me wonder if the 8800GTS 640Mb could really handle 1920x1200.
Of course, with short card lifespans, I'm apprehensive to spend another $150 on the GTX.
(I don't think I got my cash out of the 7900GTX, more so that FX-60)

Any advice?

 

[SuperKeijo]

Well all I know is I played GTR 2 with everything maxed out at 2560 x 1600 4xaa on a 8800 gts 640 without any problems. I think those games are more cpu limited..

 

[spaceman]

yup a GTS will do fine for those games. DIRT is another matter. I would not try that game at max without a GTX. On less than high levels though the GTS would do fine at any res on any game.