To take a quick look at overclocking we fired up AMD Catalyst Control Center and used AMD Overdrive to overclock the XFX Radeon HD 7850 1GB Core Edition video card.
The XFX Radeon HD 7850 1GB Core Edition comes clocked at 860MHz on the core and 1200MHz on the memory from the start. By using OverDrive in CATALYST Control Center (CCC) you can raise or lower the clock frequencies within the parameters set by AMD. For this card AMD set limits for this particular BIOS to 1050MHz on the core and 1450MHz on the memory.
We used CCC and found that with the power control settings maxed out at 20 we could
hit 1050MHz on the core and 1325MHz on the memory before any artifacts
started to show up in our benchmarks. The Elpida GDDR5 memory chips that XFX used on this card were unable to run any higher than 1325MHz. The core clock speed can likely go higher and can if you install a 3rd party overclocking utility that allows higher clock speed adjustments.
We are happy with this overclock as we are 190MHz over the default core clock speed and 125MHz higher on the 1GB GDDR5 memory.
Let’s take a look at some Futuremark 3DMark11 on the performance preset to see how the overclock helped performance.
XFX Radeon HD 7850 1GB Core Edition at 860MHz core and 1200MHz memory:
XFX Radeon HD 7850 1GB Core Edition at 1050MHz core and 1325MHz memory:
We tried out this overclock with Futuremark 3DMark 11 on the performance preset and saw the score go from P5731 to P6741, which is a 17.6% improvements from the cards factory settings. Not a bad overclock and a major performance increase for free!