We've been told that there's a publicly available 64-bit version of DiVX, but we certainly couldn't get our hands on it in time for testing. So the following test is a 32-bit DiVX encode driven in Windows XP Pro x64 Edition.

Benchmarks with XMPEG / DivX v5.2.1 - 64-bit mode Video Encoding Performance

Much the same as we saw in our 3D Studio Max 64-bit test, the Pentium 4 Extreme Edition and Pentium 4 660 have a commanding lead over the Athlon 64s. As is also the case here, we see 64-bit OS performance with this 32-bit application test; looks to be about 4% to 5% slower for the Pentium 4. However, the Athlon 64, not surprisingly because it has had longer to mature in the 64-bit space, takes much less of a hit between 32- and 64-bit modes.