Using HandBrake to encode a small video file, the Core i7 2600K achieved 86fps on all three LGA1155 motherboards making it significantly faster than the 76fps of the Phenom II X6 1100T.
There was a noticeable performance gap between the LGA1155 motherboards when testing with the x264 HD Benchmark. That said, only 4fps separated the slowest board from the fastest while the Gigabyte Z68XP-UD3-iSSD was just 1fps slower than the Asrock P67 Extreme6.
The last encoding test is based on TMPGEnc 4.0 XPress where we converted an AVI file to MPG. This took the Core i7 2600K processor just 6 minutes and 10 seconds on the Gigabyte Z68XP-UD3-iSSD -- a whopping one second faster than the Asrock Z68 Extreme4.