According to benchmarks, 2 7900gts are better than x1900xtx, but not by a huge amount, and not once the resoultion gets to 1600*1200. Now these are with drivers Nvidia sais are buggy so maybe the 2 gt's will pull farther ahead in some areas, but as of now, they are better. Just not by a huge margin. Good enough for me to get 2 though..
C2 Q6600 @3.6
2- 1GB Crucial Ballistix DDR2 1000(1100 @5-5-5-12 2.2v)
2 EVGA 280GTX in sli
2 WD Raptor 74GB(RAID0)
1 WD Raptor 150GB
X-FI Fatal1ty Edition (Beyerdynamic DT770/80 with PA2v2 amp)
PC P&C 1 Kilowatt PSU
Dell 3007 WFP 30" LCD
LG 18x DVD/CD RW
Silverstone TJ09 (5-120mm Sythe S-Flex fans)-Best case on the planet...
Watercooled. Iwaki MD20RLT>PA120.3(6 fan push/pull)>Apogee GT>2 MCW60's>T-line