Because video editing (or viditing as Mike prefers) has become THE reason to own a pc on '04, almost every benchmark will include an MPEG2 or MPEG4 rendering test. Historically, Intels have outperformed AMD in the encoding stakes, but this is starting to change. Perversely, even applications that SUPPORT hyper threading (HTT) can take longer to render when HTT is left on. Crappola.
Going a bit deeper, the new 64bit athlons seem to have the edge over the 32bit Pentiums - they're giving the same or better "performance per buck", but are clearly the better upgrade path if you're thinking of "going 64bit" as soon as the relevant windows version pops out of Microsoft. You may also notice that the AMD route is no longer significantly cheaper for the high end athlons.
http://www.tomshardware.com/cpu/2004...4_4000-11.html
A new name to look out for at the top-end of the processor market is Nocona. This is represents Intel's admission that they got the 64bit approach all along - and are now going the same route as AMD. So if you're going to go the dual processor way, look at these:
http://www.tomshardware.com/cpu/2004...s_xeon-33.html