Performance Issues.... even on medium low

[Foofighter]

Hello

I am running on the following pc:

Win 7 64Bit
Sapphire Radeon HD 5850 Toxic OC 1GB with ATI 11.3 drivers
Pentium Core Duo E6850 3Ghz
4Gb's of RAM

I would have hoped that at least it should be playable and stutter free on medium/low settings... However there is a continual stutter every few seconds..

Oh an not that I should probably even get close to it but AA doesn't work at all even if you force it...

I really hope they are looking into performance optimizations.
Thanks,
G