ReiserFS is a general-purpose, journaled computer file system designed and
implemented by a team at Namesys led by Hans Reiser.ReiserFS is currently
supported on Linux and may be included in other operating systems in the future.
Introduced in version 2.4.1 of the Linux kernel, it was the first journaling
file system to be included in the standard kernel.

Check out this other link:
www.ubuntugeek.com/how-to-increase-ext3-and-reiserfs-filesystems-performa\
nce.html

I would say that you most likely have it and don't know it.