Hi Rahul

It is a bit involved, but not very difficult to setup HPL.

First get the Goto BLAS/LAPACK from TACC:
http://www.tacc.utexas.edu/tacc-projects/
Install it using the Gnu compilers.

Then get HPL from Netlib:
www.netlib.org/benchmark/hpl/

Tweak with the Makefile to point to your mpi wrappers,
and to the Goto Library.
Build HPL.

Read the TUNING file that comes with HPL.
It has important information about the input parameters.
The main ones are N, and P,Q.
www.netlib.org/benchmark/hpl/tuning.html

First, to test, run HPL in a single node or a few nodes,
using small values of N, say 1000 to 20000.

The maximum value of N can be approximated by
Nmax = sqrt(0.8*Total_RAM_on_ALL_nodes_in_bytes/8).
This uses all the RAM, but doesn't get into memory paging.

Then run HPL on the whole cluster with the Nmax above.
Nmax pushes the envelope, and is where your
best performance (Rmax/Rpeak) is likely to be reached.
Try several P/Q combinations for Nmax (see the TUNING file).

I hope this helps,
Gus Correa
---------------------------------------------------------------------
Gustavo Correa
Lamont-Doherty Earth Observatory - Columbia University
Palisades, NY, 10964-8000 - USA
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Rahul Nabar wrote:
I've never had a cluster large enough to matter but I was thinking of
running the Linpak-HPL benchmark (from the top500 site) just out of
curiosity of knowing my actual teraflops. For one, it would tell me
how much my Rmax/Rpeak so that I know how non-optimal my network and
other infrastructure was.

Question: How difficult it is getting that benchmark to run? Was eager
to know of opinions from sys-admins who've "been there, done that".
 If it was a horrendously difficult process I might just skip it. Some
their tuning sections were scary.

Are there any good pointers on tuning parameter selection or ready
made makefiles? I had a Intel Nehalem processor and a regular Gigabit
network.



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