If you recall our Radeon HD 7970 reference board review not too long ago, we got our card to overclock to 1125MHz core and 1500Mhz memory, limited by a bios controlled clock ceiling and lack of voltage mod tools. Things changed on this New Year's weekend though...
With core voltage bumped from 1.15v to 1.25v using publicly available software and a special bios (9th Jan reveal), we got the core clock speed up to 1267MHzTest Setup:At 100% fan speed and overvolted, the GPU temps were still only a lukewarm 66 degrees celcius - which implies that the reference cooling solution could probably handle a lot more voltage
Update 2/1/12: These were the latest Furmark 1.9.2 Xtreme burn-in settings used (imgur: the simple image sharer) - different card but same settings. Even on the other benchies and BF3 (which walls the CPU to 99%), didn't see the temps go above the magical 66 degrees (toasty Singapore ambient), measured by onboard i2c sensor and ma fingers.
3DMark 11 1.03 Performance Preset (stock is P8227)

3DMark 11 1.03 Extreme Preset (stock is X2764)
Unigine Heaven 2.5 (stock is 69.6fps)ComputeMark (stock is 5920 marks)
The 28nm process and new GCN architecture have really done wonders for the performance and frequency headroom (VR-Zone Legend Shamino has achieved way better - 1.7GHz+ on LN2). Considering that the the temperatures were still in the 60s on full load, we simply can't wait for the software controlled voltage ceiling (currently 1.25v on the software we used) to be raised to push our clocks higher!. If you have a 7970 and good soldering skills, visit Shamino's Lair at kingpincooling forums for his guide on the HD 7970 measuring points and hardware vmods.
STAY TUNED FOR OUR POTENTIALLY RECORD BREAKING HD7970 4-WAY CROSSFIRE FEATURE THIS UPCOMING WEEK!