The former information on this page was obsolete over a year ago. MarkLinimon has been running 11.1R for some time, albeit booting from NFS.
The 9133 is a Power5 system. Either 1 or 2 CPU cards are supported. Each has either a 2-core or 4-core processor.
Now that the Talos machines are shipping, this machine should no longer be recommended for new work.