Encoding is something most of us do on a fairly regular basis and it is a good way to monitor any fluctuations in performance across the range of motherboards on test today.
One of our favourite tools is the excellent, free Handbrake. HandBrake is an open-source, GPL-licensed, multiplatform, multithreaded video transcoder, available for MacOS X, Linux and Windows.
We extracted a VOB file from the DVD of AVATAR and then converted it to MP4 at quality settings.
Overall there is a five second difference between the boards which would translate to a benefit of several hours over a weeks intensive encoding work.