games for directX10 or play in winxp

If a game is made for directX10 like Bioshock/World of Conflict/etc. Is it only gonna help in the visuals or also in the FPS?
I asked this because I ran WOC on my home computer that has winXP and Vista ult. Vista ultimate has better visuals for sure. But it seemed to run anywhere form a few fps to 10+fps slower than in winxp. Is it because of the added visuals or because Vista is slow? I'm contemplating if I should dual boot my Asus G1s-B1 and play games on the sides that is faster. Which is WInXP, or will I be missing out on visuals?

 

The DX10 coding is going to improve visual quality and lower fps. Also, the Vista OS is slower, causing a slight fps drop.

 

actually some games run slightly better in dx10 then their dx9 counterparts, dx10 is much more efficient then dx9 so in theory the same visual setting should run better in dx10. There are however some issues, the drivers just aren't nearly as mature as they are on xp. This will improve over time and it has already greatly improved. Also, dx10 offers new visual effect not previously possible and when developers choose to use these gpu intense effects that aren't in dx9 surely the game will run slower then in dx9 without the effects. Hope that helps

I've seen allot of bioshock benchmarks where it does run as well if not better in dx10 although from a visual stand point nothing much was added to the dx10 version it just used the more efficient code.

 

I've never seen a game run better in DX10 than in DX9 on any graphics card. Bioshock runs relatively equally on either with high end cards http://www.firingsquad.com/hardware/bioshock_directx10_performance/page7.asp
but then at high settings the visuals are relatively equal as well. The "efficiency" being discussed with regards to DX10 is usually the ability to produce higher image quality with lower settings, not the ability to run faster at the same settings.

 

Hard ocp review

Hard ocp finds dx10 just barely ending out dx9 although its close, give it time, I think in the next 6 months after drivers mature some more and sp1 comes out we'll see dx10 out pacing dx9 (when comparing apples to apples)

 

I've read that review, but if you look at it closely you'll notice they used only the most powerful DX10 cards and didn't test it at the highest settings (WUXGA with max in game settings). If they had tested it at those settings on mid range cards (8600GT/GTS, HD2600XT) or at highest settings with the more powerful cards, I'd almost guarantee you that DX9 would pull ahead.

 

hmm shoot. still dont know if I should install winxp or not on the g1s-b1..