When it came to audio encoding via LAME, the X3 710 @ 3.51GHz was the fastest. The stock tri-core AMD 45nm processor was slower than the Intel setup but faster than the older AMD quad-core.
Differing from the LAME MP3 results, when converting the sample WAV file to FLAC, the stock X3 710 was faster than the Core i7 920. AMD's gains continued when increasing the clock speed.
With video encoding using FFMpeg, not even the overclocked Phenom II X3 was able to outpace the Core i7 920 with its eight logical cores.