Our daily kernel benchmarking using the Phoromatic Tracker had pointed out a rather large performance boost in the Apache server performance during the Linux 2.6.33 cycle. With our AMD Opteron 2384 workstation the performance boost was not many times greater like found with the Intel Atom 230 setup, but still the speed-up we found between the Linux 2.6.32 and 2.6.33 kernels would definitely be considered huge. With going back to the Linux 2.6.24 kernel, however, we find that the Apache performance dropped significantly between the 2.6.24 and 2.6.25 releases. In other words, this Apache performance boost found with the Linux 2.6.33 kernel is not pushing its HTTP serving performance into new territory, but rather it is actually just returning to its pre-2.6.25 levels. This Apache regression had lasted in the Linux kernel for eight releases.
This test system was using the EXT3 file-system and we found its TPC-B database performance to improve by many times between the Linux 2.6.29 and 2.6.30 kernel releases. In fact, the Linux 2.6.30 kernel was 770% faster than its predecessor was and it remained that way with the Linux 2.6.31 kernel and then regressed only slightly with the Linux 2.6.32 kernel. With the new Linux 2.6.33 kernel, however, the PostgreSQL performance atop the EXT3 file-system has fallen off a cliff. Not only has the PostgreSQL performance lost its gains made during the 2.6.30 development cycle, but also with Linux 2.6.33, it is actually much slower than it was in any of the pre-2.6.30 releases.
The 7-Zip compression performance fluctuated some between kernel releases, but in the end with the Linux 2.6.33 kernel is where 7-Zip is performing the best. These are the charts we like to see.
The LZMA compression performance had little impact between Linux kernel releases.