I've currently have two 7800GTX 512MB in SLI mode and I'm finding out that very few of the games I use (GTR, GTL, FS2004) actually support SLI. After reading the issues with shaders on the 7800GTX 512MB and seeing some impressive results from the ATI X1900XT 512MB, I'm wondering if ATI really have the upper hand and if I should dump my two 7800GTX 512MB's for a single X1900XT 512MB.
If the games you play don't use sli then I'm sure it seems like a wast to you. Comparing sli and cf still is not fare yet IMOP sli has been out for alot longer that cf. You have to think of the future though, you won't be playing those same games for ever and most of the newer games and games to come support sli.
GTL (GT Legends) is a newer game. Unfortunately there are no details on what FS X will do in terms of SLI support, FS9 currently has major problems with SLI.
AOEIII and LORII may support SLI, but I've ran both with and without SLI enabled and there is no significant different in visual performance. With the exception of COD2, none of my games seem to show any benefits from SLI. With the exception of artificial benchmarks such as 3DMark, I can't see or notice any real frame rate benefits from SLI in 95% of my games.
I run 1920 x 1200 exclusively and from the reviews I've seen this is where the ATI X1900XTX 512MB seems to shine especially at High Image Quality settings.
I'm not sure what is going on with nVidia, but cranking up image quality and using shaders seems to really impact performance and SLI isn't helping in many cases.
But I think you folks are correct...perhaps a wait and see what comes out next is the smarter decision rather than move to ATI.