I've left indexing on because I think it's a useful feature and I understand that Win7 is "supposed" to not do it during games.

[...] What is this and how can I check it?

Check Win7 isn't HDD Cacheing, It did that to me quite a lot of initial install which just destroyed my FPS. Thats definately a software problem, that system is easy capable of 60fps+ with a config.

[...] Yes. I left it on DX9, didn't change settings and measured average framerate over 30 minutes or so.

[...] And you've determined that all of the following parameters are true: - They are both using the same release of DX (WiC has a DX10 mode, so it is quite possible it may have changed DX version when you switched OS) - No settings which may affect performance have been altered - You get the same average framerate over a reasonable period of time within a small margin of error

[...] World in Conflict performed equally well for me on XP as it does on W7.

[...] My point was based on arithmetic and logic tests that I've done, the comment about games was an afterthought. If you can find me a game which does not alter settings between operating systems which performs better in DX9 or lower on 7 than XP, I'll eat my hat, and my shoes, and I'll even pose for nude photos at LAN.

Chris not wanting to start a flame war, but in your 'experience' windows 7 sucks up framerate Windows 7 games performance compared to XP varies alot from game to game (most NEW games perform better in Windows 7), google it, you will find a +/- 10% max difference. in most games this is < 2%

Still, I don't see why you would suggest someone uses an 8 year old operating system with a huuuge number of security flaws just so a Video Game runs a little better....

@ 1280*1024, i'd expect that rig to hit 60-70 FPS minimum without running any FPS cfg OP I assume you have verified integraty of game cache, and defragmented cache files? *edit* If you are playing in windows mode, change back to full screen as windows mode does have a FPS hit