Simply put, it is a reproducible measure of how fast your machine can encode a short HD-quality video clip into a high quality x264 video file. It’s nice because everyone running it will use the same video clip and software. The video encoder (x264.exe) reports a fairly accurate internal benchmark (in frames per second) for each pass of the video encode and it also uses multi-core processors very efficiently. All these factors make this an ideal benchmark to compare different processors and systems to each other.
We scaled this chart to the second pass which is the more CPU intensive of the two. The Intel Sandy Bridge CPUs have a great showing here, aside from the Core i3 2100. The i5 2500K is just over 1fps behind the Core i7 875K in the 2nd pass, but 23fps faster on the first pass. Overall the i5 2500K would finish the encoding quicker!
In what is going to be an ongoing trend, the Core i7 2600K dominates the x264 HD Benchmark. It’s 26fps faster than the AMD Phenom II X6 1090T on the first pass and 5.6fps faster on the second. When overclocked its performance sky rockets an awesome 25%!!