Framerate issues on monster system

[WhiteKnight]

SSAO on high is simply extremely demanding and SSAO on low and with 8 or 16 samples looks good enough. A higher setting is simply overkill.

Hi Thomas, while that may be true, my system should be way more than capable of running the game at MAX settings with 16 samples and SSAO set to high.

Since I have a dual boot, I tested the game on Windows XP Pro 64-bit with high SSAO and 16 samples and it does seem to run smoother than in Windows 7 ultimate. Why would this be? Is this game not optimized for Windows 7?