http://www.nfsnet.org/

http://www.msu.edu/~bercikda/rank_math2.html

Saw was being ranked now and could not find a AMD Users team. Did see it would run diskless:

"Can the NFSNET Client work in clustered environment which may or may not be diskless?
Yes, clustered environments are supported, including diskless clusters. For instructions on how to configure for these environments, please contact the NFSNET admin team."