iTunes wants higher clock speed to deliver quick audio transcoding performance. Hence the small time difference we saw doesn’t come as a surprise.
We'll fairly call this one a tie.
DivX transcoding from MPEG-2 is only slightly quicker on the Phenom II X4.
Xvid transcoding benefits a bit more, although the process takes much longer than transcoding MPEG-2 into the DivX format.
MainConcept gets its performance from core count and clock speeds. There’s no noticeable benefit from the L3 cache here.