When AMD released the 5770 it had default clock speeds of 800 MHz for the core and the GDDR5 memory was clocked to 1200 MHz/4.8 GHz. HIS improved on those speeds when they released the factory overclocked IceQ 5 model. They bumped the core speed up 75 MHz beyond reference speed. As we mentioned earlier the Samsung GDDR5 chips are rated or theoretically capable of operating at 1250 MHz. HIS has increased the speed to the maximum rated 1250 MHz.
We used the Catalyst Control Center Overdrive feature to manually push the card even further. We managed another 75MHz on the core topping out at 950 MHz and we managed to gain an additional 80 MHz over and above the rated specs on the GDDR5 which is actually quite impressive. The temperatures of our review sample only increased slightly after increasing the factory overclocking to our maximum stable levels which once again shows that the cooler is doing a decent job.
HIS have done some homework and increased performance across the board. Thanks to their engineering skills and excellent cooling provided by the IceQ 5 cooler they have released a quiet yet powerful graphics card at a reasonable price.