Ubuntu 9.04 vs. Fedora 11 Performance
When encoding an Ogg file it was more favorable on Ubuntu, but by a barely significant difference.
The time it took to encode an AVI to NTSC VCD using FFmpeg 0.5 was essentially dead even between the 64-bit versions of Ubuntu 9.04 and Fedora 11.
The GMPbench performance was very close between Ubuntu and Fedora.