2 XFX 5970 (1000/300) ~870 Mhash/sec 
Great speed on the cores, what voltage are you running the cores at to get them to 1000.
Well... 1,163 V
(OC Tool: http://www.techpowerup.com/downloads/1641/AMD_GPU_Clock_Tool_v0.9.26.0_For_HD_5870.html )System: M$ Win7, Mobo: Asus P5Q PRO, PSU: 850 W
XFX 5870 V 3.0
