This article compiles the best benchmark results we collected of various CPU models using x264 HD Benchmark 4.0, a free CPU benchmark developed by graysky, Dashken and Adrian Wong. This CPU performance comparison guide currently covers 84 different CPU models plus another 283 CPUs in the older comparison but this is just the beginning. We will keep updating the results as new results come in, so please contribute your results.

If you would like to participate in this endeavor, head over to the x264 HD Benchmark 4.0 page and download a copy. After you obtain your benchmark results, simply post them in the official forum thread of x264 HD Benchmark 4.0. Please post your results even if your processor is already listed in the comparison. This is because we will use your results if they are better than the results currently listed in the comparison.

Here is the list of updates :

- Added the Intel Core i7-2600K desktop processor (overclocked to 5.18 GHz).
- Added the Intel Core i7-970 desktop processor (overclocked to 4.25 GHz).
- Added the Dual Intel Xeon X5650 workstation processor (overclocked to 2.8 GHz).
- Added the Intel Xeon W3565 workstation processor (overclocked to 3.33 GHz).
- Added the Intel Xeon E5540 workstation processor (overclocked to 2.66 GHz).
- Added the Dual Intel Xeon E5430 workstation processor.
- Added the AMD Athlon II X2 220 desktop processor (overclocked to 3.26 GHz).
- Added the Intel Core 2 Duo E4700 desktop processor.