The ASUS EAH5870 MATRIX Radeon HD 5870 card saw an 70-percent increase in core clock speed.
This forum post over on Xtreme Systems claims that community members Elmor and Kinc managed to overclock an ASUS EAH5870 MATRIX Radeon HD 5870 card (2GB) to a crazy-fast core speed of 1525 MHz (core), making a 70-percent speed jump over the default core speed of 894 MHz (850 MHz for the reference card).
The memory overclock wasn't quite as spectacular, cranked up to 1300 MHz, showing a rather pleasant 8.3-percent increase. The overall process remained quite stable at the 1500 MHz point, proven with the use of 3DMark Vantage and scoring P29342 points at the performance reset.
The duo kept the overclocked card cool by using liquid-nitrogen evaporators. The bench also featured an Intel Core i7 980X Extreme Edition six-core processor clocked at 4492.9 MHz, an ASUS Rampage III Extreme motherboard, 6GB of Corsair Dominator GTX DDR3 memory, and an Antec 1200W power supply.
The forum post displays all the validating credentials such as the bench, 3DMark Vantage screens, and CPU-Z screens. "Around 1525-1550/1325-1350 should be possible with more time on this one," the post claimed.