Crysis with nvidia 8600gts

Hi guys, This is my first post in this forum, so if I make a mistake please excuse me.

My old pc was having problems, so I have build a new system before two months with these:-

Intel Core2Duo E6750
Asus Commando
2GB DDR2 800MHZ
XFX nvidia 8600GTS
120GB Hard disk (old one, may upgrade later)
Windows vista home premium 32bit

I tried Crysis demo on it in DX10, first I make the game put the perfect setting for my system, so far it is all in the middle. Then I started the game, everything was working nice. Some problem is some areas (because of the graphic card) but the over all was really nice.

I am just wondering, can I get a better performance with the game if I change the game play from DX10 to DX9? or maybe going to vista 64bit?

Note: I know that some people with recommend the 8800GT for the game. But I cant change the graphic card now.

And thank you in advance.

Agreed. 64 bit shows minimal improvement whereas moving to DX9 doesn't lose much quality (especially at lower settings) yet greatly improves the frame rate.

No it isn't (8600gts, 8800gts 320, 8800gts 640, 8800gt, 8800gtx, 8800ultra - and thats just the nvidia cards)

Remember vista SP1 should be out soon and Im sure microsoft is holding back some performance upgrades that will make SP1 look worthwhile so it may be premature to throw out vista and go back to XP.

The 8800GT is definatly worth looking into somewhere along the line unless there is something better at the time.