A few months ago I built a system consisting of these parts:
Foxconn A7DA-S 3.0 AM3 790GX mobo
XFX Radeon 4890 1Gb gpu
AMD Phenom II X4 955 3.2Ghz CPU
4Gb DDR3 Kingston RAM
500GB WD Caviar Black HD
OCZ 600W 600MXSP PSU
NZXT Guardian 921 case
I'm running Windows 7 RC as my OS (will be upgrading to full edition when it comes out).
I've noticed that this computer hasn't been quite living up to my expectations. I mean, don't get me wrong, it runs much smoother than my old computer. But it should blow away a game like WoW and I'm constantly seeing drops in frame rats to mid 30s-40s when I get into even semi-congested areas (e.g. 15v15 BGs, not even the bigger ones).
So I ran both 3DMark06 and 3DMark Vantage and to my suspicion my system isn't really running at what it should be. The numbers:
3DMark 06 Numbers
3DMark Score: 15986 3DMarks
SM 2.0 Score: 6429
SM 3.0 Score: 7446
CPU Score: 4430