Low fps

I am getting low fps while running 5 instances of WOW, only about 15fps on each instance.
This is a new machine that I built myself.
Intel QX9650, DFI LP X38 motherboard, two HD3870 graphics cards with 512mb memory, PCP&C 750 watt PS, 4gb Mushkin DDR2 800, 2 WD 320gb HDD, Vista Ultimate 64bit.
I am running 3 monitors, a 24in on one card and 2 22in on the other card. Using extended desktop.

Edit: forgot to mention the 22's are in portrait mode

Vista is a huge resource hog.... 64bit has poor driver support.