Nvidia 8800gts 512mb or Nvidia 9600gt 512mb SLI

Its time to upgrade my graphic card. My current video card Is starting to lag new games at highest settings. I dont know if to get 8800gts 512mb or 9600gt in SLI. Will 9600 SLI performs better than 8800 gts g92 or 8800 gtx? I will be gaming at 1900x1200. My budget is no more than $400.
my current pc specs are:

ATI 1950 512mb
XFX MB-N680-ILT9 680i mobo
3gb ddr2 Patriot pc2-6400 LAT:4
650w Corsair Power Supply
E8400 OC 5.1ghz water cooled
NEC 22'' CRT 2048x1536
My own customize Win XP Lite

sli is always inferior to a better card, in your case the 8800GTS is always the better choice. it runs cooler, it uses less energy, it out performs and cost less

there are only 2 scenarios when sli should be used:

1) existing card can be sli'ed, that is you have a system and you want to upgrade the system add a second card.

2) top of the line gpu - in this case th 8800gtx or 8800gts-g92 are the only cards that should be sli'd a new system

sli gives 40-50% performance increase - you lose 50%

Thanks for your replys. Most of the games I play they all support SLI. I only play FPS games and tacticals. I think 9600 gt sli is the best choice for me. Im also will start playing at resolution 2048x1536, and heres when sli will start using its real power.

Here's a few site with 9600gt sli benchmark, and some of them include a 8800gts 512mb to compare...

http://en.expreview.com/2008/02/23 [...] w/?page=15

http://www.firingsquad.com/hardwar [...] /page9.asp

http://www.neoseeker.com/Articles/ [...] ic/14.html

SLIed 8800gt's would be even better. It appears the SLI 9600GT's have an advantage over a single GTS according to those charts.

What can you get 2 9600Gt's for? compared to 8800GT's compared to 8800GTS's? Get what you can afford and run with it. Thats a high res and you are going to need the Ummfff!