When measuring how long it took to build out PHP 5.2.9 on each distribution, it was faster on Ubuntu by about four seconds. Ubuntu 9.04 is using the older GCC 4.3 branch while Fedora 11 is using the newest GCC 4.4 series.
Ubuntu 9.04 had really smacked Fedora 11 when it came to the Apache Benchmark with the static web page serving performance. Ubuntu was able to sustain more than 58% more requests per second than Fedora 11.
At encoding an MP3 file using LAME, the lead was in Fedora's favor but by just about 4%.