Also possible its not getting enough power so underclocking its self.
Currently running 830/1250 so normal clock position on the cards.
Fractal Design Define R3
AMD Phenom II X4 840 (4 x 3.2 GHz) AM3 2MB
AMD Heatsink & Fan
Corsair 2GB XMS3 PC3-10666 1333MHz (2x1GB)
2 x ATI Radeon HD 6990 - (XFX) CrossFireX Setup
Asus Crosshair IV Extreme (AMD 890FX)
Motherboard Integrated HD Sound
Integrated Ethernet Lan (Broadband Ready)
Cooler Master 1000W Silent Pro
500 GB SATA-II HDD 7200 8MB
Samsung (SH-D162D) 16x DVD-ROM - Black (SATA)
Microsoft Windows 7 Professional 64 BIT
GPU-Z shots - Check out the shaders and texture fill rate?
??
Good Core:http://img585.imageshack.us/img585/2937/ok6990core.gifProblem Core:http://img600.imageshack.us/img600/1500/problem6990core.gifCheck out 8 CU on first core when starting Diablominer..
http://img607.imageshack.us/img607/8104/8cu.jpgHave tried with and without Crossfire enabled with a dummy plug.... no joy.
Thanks
D