The benchmark requires tuning to get good numbers. I really don't recall what the default tuning is on the released versions, and I don't make any effort to ensure that the results will be good. Please see the forum post
http://www.nabble.com/How-to-get-big-numbers-with-the-HPL-benchmark-td19685268.html for more information.
If you or anyone else comes up with a good tuning, I'd be happy to make it the default.
Cheers, M.