Overclocking ATI HD 4770 Beyond The Limit
 

What we gathered from the different reviews published today is that they almost all reach the 830Mhz overclock on the GPU, which is the maximum the ATI Control Center allows. It takes a small edit of Rivatuner to go beyond and unlock the full potential of the HD 4770; Expreview wrote this last week:

If you want more, just open the Rivatuner.cfg, find “RV770 = 9440h-9443h,944Ch”, and add the ID “94B3h” after.

This allows you to use Rivatuner to overclock the GPU/MEM on the HD 4770 beyond what CC allows! PCGamesHardware used this trick to overclock their HD 4770 sample to 900/1000; it's safe to say that even a 830Mhz GPU OC will push the HD 4770 past 4850 performance, the 900Mhz GPU overclock is icing on the cake:


This overclock was achieved with the stock cooling (@ 50% fan speed), a better cooler might push this OC even further. Performance wise you can see that a 20% OC on the GPU (25% on MEM) translates roughly in 26% FPS increase... which is very promising. And as you can see in the chart, the overlocked HD 4770 pushes past 9800 GTX and HD 4850 with a nice margin.