More similar results... This time with dcraw as we measured how long it took to convert several files from RAW format to PPM files.
The Minion constraint solver with the Solitaire benchmark also was close between Ubuntu 9.04 and Fedora 11.
Fedora 11 did much better than Ubuntu 9.04 with the SQLite performance. This large difference is explained by a serious kernel regression we previously reported on several occasions in the past, but after being present in the kernel for several releases, it was finally fixed with the Linux 2.6.29 kernel. Ubuntu 9.04 with its Linux 2.6.28 kernel is still impacted by this SQLite regression, but should be fixed in Ubuntu 9.10 unless the regression reappears. Fedora 11 is also using EXT4 by default while Canonical is finally moving to this updated file-system with Ubuntu 9.10.
Fedora 11 not only did better with its SQLite database performance, but PostgreSQL ran much faster too under the operating system that's codenamed Leonidas.
In a number of the benchmarks the results were close, but in a few areas there are some major performance differences. In particular, with the test profiles that stress the system disk, Fedora 11 generally did much better -- in part due to the EXT4 file-system and newer Linux kernel. Fedora also did much better with the database tests like SQLite and PostgreSQL. Ubuntu 9.04 though had done a better job with the Apache Benchmark and C-Ray. You can run your own benchmarks and compare these results using the Phoronix Test Suite.