The Blowfish encryption performance measured in John The Ripper was very close between Ubuntu 10.04 LTS, openSUSE 11.3 RC2, and RHEL 6.0 Beta 2 while CentOS 5.5 and its older kernel had fallen behind.
The IS.C test within NASA's NAS Parallel Benchmarks were close between Ubuntu, CentOS, and openSUSE but RHEL 6.0 Beta 2 had lost out.
The TCP loopback network performance test would not work on openSUSE, but Red Hat Enterprise Linux 6.0 Beta 2 was the fastest with its network performance when compared to Ubuntu 10.04 LTS and CentOS 5.5.
Well, out of these eleven tests, openSUSE 11.3 RC2 was the fastest five times while Red Hat Enterprise Linux 6.0 Beta 2 was just fastest with the LZMA compression and loopback TCP network performance. CentOS 5.5 had secured three first place finishes and Ubuntu 10.04 LTS had just two wins against this benchmarking foursome. Of course, Red Hat Enterprise Linux 6.0 is still in beta and is not expected to be finalized until the end of this year, so debugging code and other ongoing work may be making it run marginally slower right now, but we will be back with more Red Hat Enterprise Linux 6.0 benchmarks as soon as new test versions are available.