Curious to know how the performance of enterprise Linux (RHEL, CentOS, Scientific, etc) evolves over time? Here's a look at the performance of Scientific Linux 5.7, the recently released Scientific Linux 6.2, and then Fedora 16 as representative of what will eventually work its way into Red Hat Enterprise Linux 7.
Scientific Linux 5.7 ships with the Linux 2.6.18 kernel, GNOME 2.16.0 desktop, X.Org 7.11, Mesa 6.5.1, GCC 4.1.2, and an EXT3 file-system.
The latest Scientific release, Scientific Linux 6.2, meanwhile ships with the RHEL 6.2 package set: Linux 2.6.32, GNOME 2.28.2, X.Org Server 1.10.4, Mesa 7.11, GCC 4.4.6, and an EXT4 file-system.
Lastly, Fedora 16 was tested with the Linux 3.2 kernel, GNOME Shell 3.2.1, X.Org Server 1.11.1, Mesa 7.11.2, GCC 4.6.2, and an EXT4 file-system.