I'm using 3833 which gives me about 30-40 fps. Latest revs up to 3882 have a big slow down for me. Probably there's another rev which works better than 3833.
Rig
*Corei5 3570K *Nvidia 9800GT 1GB DDR3
*Motherboard Asus P8H77M-PRO *Win7 x64
*RAM 8GB DDR3(1600)