Benchmark Results: Audio and Video Encoding
Both iTunes and Lame appear to be either single- or dual-threaded at best, scaling evenly with clock speed for Core i7, Core 2 Quad, and Pentium dual-core processors.
Using TMPG, the DivX codec gets a small boost from the $5,000 machine’s Core i7 architecture, while Xvid appears unaffected. The DivX distinction is likely due to Core i7’s added memory bandwidth.
Mainconcept results are a little more difficult to interpret, but it appears that extra cores, extra speed, extra cache, and extra memory all play key roles in optimizing its efficiency.