Well I finished my upgrade today, I now have
AMD 9850
Ati Radeon 4890 1GB Clocked to 920Mhz core and 4400Mhz ram
4Gb Ram
Windows 7 64 Bit
I upped my settings to High/very high and in the editor my FPS with 5-6 squads fighting went to 50-75 steady - so far soo good!
In the campaign in the first big mission where you have to find the guy (no spoilers!) as soon as I enter the first city it drops to 20-30 fps!
I dont know what the heck is causing the slow up, aside from buiying an i7 My spec cant go much higher :(