To overclock the reference Radeon HD 4670 graphics card, I used ATI Overdrive that is part of the CATALYST Control Center. When you ‘unlock’ the ATI Overdrive, you can manually set the clock and memory settings or let the ‘auto-tune’ utility set the frequencies for you. Just for fun, I tried out the auto-tune feature to see if it could really find a stable clock configuration and it worked in just a few minutes and did not lock up the system. Before I dive deeper into overclocking I wanted to point out that at idle the GPU core clock runs at 165MHz and the memory runs at just 250MHz in order to save power. CATALYST Control Center showed that the GPU temperature was just 32C, which is great for any discrete graphics card at idle.
When the auto-tune utility starts up a new window will open and the graphics card is overclocked. This utility determines the highest core and memory clock frequency that is stable and shows you what the GPU temperature is and how much load the GPU is under during testing. While the Radeon HD 4670 was just 32C at idle it jumped up to 81C when under load and overclocked!
I started out at 750MHz on the core and 1000Mhz on the memory, but was able to reach 790MHz on the core and 1040Mhz on the memory. This is a 40MHz overclock on the core and 40MHz on the memory. Not a bad overclock, but this is just a 5% overclock on the overall GPU frequency.
To test out the overclock I fired up 3DMark Vantage again and ran the benchmark with the new clock frequencies. The score went up 86 points, which was an improvement of 6.7%!