Ya but that doesn't say how much processing power it take:
http://www.extremetech.com/computing/16 ... pectations
(page 2 is more interesting)
*I* encode alot of movies, using x246 (h.264 variant), usually I encode a movie 160% slower than the runtime. A 90 minutes movie can easily take 2h30-3h to encode. To think it could take 12 to 36 hours to encode... wow! But as I've read, the quality would be better, and the filesize would be lower.
So even if "your" encoder has something wonderfully fast to it, and chopped those in half, it's still way too processing hungry.