Got a pair of 7970s running at core 1075 (stock 1000 Mhz) and memory 1200 (stock 1425), stock volts. Card is voltage-locked unfortunately. But I cannot get memory ro run at less than 1200. Any lower, and system crashes.
Any idea why? Others seem stable at much lower memory underclocks!
Do you have your driver updated to the most recent one? Do you use Windows? I've heard that for Linux with certain versions of FGLRX, dropping below the recommended clocks does weird things. Definitely try re-installing the driver,