My main question... Is directX10 worth the performance cost of upgrading to Vista.
-AMD 6000+ X2 at stock speed of 3 GHz.
-an 8800 GTS 320 MB version (using LCD as main monitor saw no need for higher version since res doesn't go that high)
-2 Gig Corsair DDR2
I'm currently running Vista and everything run's well for the most part (5.4 vista score... 5.9's for everything but the proc). However, I went to check out some of that DX10 eye candy so I downloaded nvidias cascade demo and to say the least it pretty much ran like crap.
So I've begun to wonder if directX10 effects are going to perform like that then I probably won't have them enabled anyway... so what exactly is the point of running Vista. Granted as I said I really can't tell a difference operationally between vista and XP with my setup, but I'm sure Vista is chewing up a lot more resources then XP would be.
In my opinion, not yet. If you were building a computer new, installing a new OS, etc, than I'd say yes because its easier to build it and not have to install Vista over XP later. Since you already have a running XP machine, then stick with it for another year, maybe two. Its going to be a while before games get developed far enough to really use Vista, as well as all the drivers that have to go with it.
Beyond that, MS is already starting toward DX10.1, so future games will use that. Guess what? Your 8800 GTS won't handle DX10.1. Yes, I have a 8800 GTS 640 and I've decided that its more of a high performance DX9 card than a real DX10 card. So until a large number of games come out that use DX10, or DX10.1, I'm not going to think about using Vista. At least not until I build an all new machine.
I have vista/XP pro dual boot... I've not actually had need to resort to XP, I have a GTS-640, 4000+ and 2GB of RAM... all my games play completely smooth on vista, so even if there is a performance difference, I can't see it.
I find the most intensive bits of Vista are the aero interface, and superfetch (which chews through memory)... I don;t mind waiting an extra 10 seconds for Mozilla to load so I just turn off superfetch.
As Sailer said, there isnt much out there that takes advantage of DX 10 yet. Really the only one is Bioshock, which does look awesome (I'm running the 8800 GTS 640 MB version). More will come in the near future with Crysis leading the way. I also dual boot Vista / XP, and while Vista is a resource hog compared to XP, people said the same thing from 3.1 to 95, 95 to 98 etc...
dx10 simply is not worth it yet... its still in the 'early adopter phase'... and nearly all games till now have been under DX9 and older, save for about 3 or so games, compared to hundreds and hundreds of older games... ...realistically you should give DX10.x another 2 years or so before its reasonably mature. by then DX9 games will be more phased out, and more DX10 features will be used, along with more optimized features and performance improvements as a result. just going by the move from DX8 to DX9, and from win98 to winxp... and no reason to think moving to DX10 will be any different.
so, another 2 years or so from now before it can really be considered a worthwhile improvement, then maybe... but by no means overnight, at least it wouldnt seem that way.