crossfire & quad core+ support?

I don't know about the CPU cores but SLI is disabled.

I'm gonna put in an extra 5850 see if it helps. Anybody on a 6 or 8 core gaming PC?

Yes im on my 8-core gaming PC. Cpu is an AMD FX 8320 @ 3.5ghz. I also have 8GB of RAM and am running an Nvidia Geforce GTX660 2GB on Win 7 HP 64-bit. Games only using 2 cores of the Cpu about 3GB of Ram and up to 65% of the Gpu. I have a 9800GT in for physx but the game has no physx. Still even tho the games not using nearly all my resources it only getting 34.3fps average and see as low as 22fps. Thats on max settings but not much better on lower ones.