Overclocking Performance

When we originally overclocked the Radeon HD 4770, we used the reference design with its stock cooler. At the time, RivaTuner didn't officially support the Radeon HD 4770 so we enlisted a little help from our friends at Guru3D who helped us with the hex codes needed for the tweaking software to talk to our sample GPU.

Adjustments made, the reference Radeon HD 4770 proved to be a very capable overclocker, with the core ramping up from 750MHz to 880MHz and the quad-pumped GDDR5 memory hitting a whopping 985MHz (3,940MHz effective). We expected the Gigabyte card, without the aid of a heatsink on the memory, wasn't going to hit such high frequencies on the memory. Though we were proved corrected, topping out at 890MHz (3,560MHz effective) is still a decent score considering it has no independent cooling and more limited power hardware.

We found that the core on on our review sample Gigabyte card was happy to go higher than the reference design and managed a whopping 905MHz overclock, a 155MHz increase on the stock speeds. A great result, and highly surprising given the cut down nature of the hardware which clearly isn't a limiting factor. Given something extreme like a voltage mod - extra capacitors and the MOSFETs would certainly benefit for more hardcore overclocking.



Overclocking graphics cards on air cooling is rarely the best way to see significant performance gains in gaming, but if the marketing guys at Tesco are to be believed, every little helps. The overclock boosted to the minimum frame rate in Crysis by 2fps at 1,680 x 1,050 with 4xAA and 1fps at 1,920 x 1,200 with 2x AA.