What is the best video encoder avi to dvd?

hi iv been useing convertxtodvd for around a year now and i have a c2d 2.66ghz 100mhz fsb and wen converting i notice that the software isent useing all my cpu speed its only running at 75% and converts a dvd in around 15min i no this is fast but is there a software out there for converting my avi to dvd that will use all my cpu speed