Guild Wars 2

My game running on xp x86 sp3, nvidia 306.81, is getting twice less the framerate it is getting on 7 x64 sp1, nvidia 306.97.

My hardware is i7 930, GA-X58A-UD3R, F3-12800CL6T-6GBTD, 6x Spinpoint F3 HD103SJ (raid 0 + raid 10 on ICH10R), and GV-N66TOC-2GD, N2200P @1600x1200×85.
xp is installed on the raid 0 array, and 7 on the raid 10, installation have been made separately so that each os ignores the other one (I choose the os by choosing the partition on which to boot).
So I tested the game on the very same computer and on xp I get a 25 fps average framerate and on 7 I get a 50 fps average framerate, both at max (available) settings.
Since some graphic options are not available on xp (because of dx9 I suppose), it should need less ressources to run on xp.
Before any useless consideration, I know it makes more sense for my hardware to run on 7 x64, but on xp I am the admin.

Should those big differencies be expected, and aside from the usual stuff in the nvidia control panel (already tested, no change), is there anything to do to improve performances on windows xp ?

Interesting observations.
Looks like I´m supposed to again throw money at somebody else so I can properly play this game.
Already dumped 90€ into a processor upgrade that made my FPS worse.
If only ANet could give us a guarantee that their kitten client would run properly, but by now I´m sure they´re just as clueless about all these performance bugs.

Damai.1947:

Since some graphic options are not available on xp (because of dx9 I suppose), it should need less ressources to run on xp.

Nope, GW2 is a DX9 game, the only thing we don´t get on XP are high res textures because of available memory issues.

Thanks for the tip about dx9, let’s hope they’ll optimize the game so we’ll get those options on xp too.
What is odd is that process explorer gives me around 3.5 GB left out of the 6 while running the game on 7 x64 and shows that gw2 takes about 1.5 GB, so technically that’s not over the 32-bits memory limit of xp.
But I know the memory is managed a lot better in 7, or so I’ve heard.
About the cpu, it is not a performance bottleneck as the gpu is, and I suspect gpu memory bandwith to be that bottleneck.
I’ve recently upgraded from GTX 275 to GTX 660Ti, before I had 15 fps average, now 50 fps … on 7 x64 ^^. I was expecting more for 300 doubloons, but at least it’s playable.