To overclock the XFX R7950 Black Edition Overclocked graphics card we used AMD OverDrive.
The XFX R7950 Black Edition is already factory overclocked and comes clocked at 900MHz on the core and 1375MHz on the memory from the start. The reference AMD Radeon HD 7950 that AMD sent us was clocked at 800MHz core and 1250MHz memory. By using 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 1100MHz on the core and 1575MHz on the memory.
After overclocking the card we found that we were able to reach 1030MHz on the core and 1575MHz on the memory with full stability. If we went up to 1035MHz on the core we would see artifacts in the benchmark, so without increasing the core voltage this is the best that we could manage. Remember, the Radeon HD 7950 started out with an 800MHz core clock, so this is an increase of 230MHz or 28.8%. This should really help out in the performance of the card and it also makes us wonder what these cards can do with extreme overclocking.
Let’s take a look at some benchmarks to how the overclock helped performance.
XFX Radeon HD 7950 Black Edition at 900MHz core and 1375MHz memory:
XFX Radeon HD 7950 Black Edition at 1030MHz core and 1575MHz memory:
We tried out this overclock with Futuremark 3DMark 11 on the performance preset and saw the score go from P7659 to P8555, which is a 11.7% improvements from the cards factory settings. The reference AMD Radeon HD 7950 scores P6926, so this is a ~24% improvement over the reference card!
In game titles like Metro 2033 the overclock is enough to beat a stock AMD Radeon HD 7970 video card and even the mighty EVGA GeForce GTX 560 Ti 2Win dual-GPU video card. The AMD Radeon HD 7900 series is very overclocking friendly as you can see.