Subject: FYI: Some ScaLAPACK performance numbers on Beowulf

From: Eugene Leitl <[email-masked]>
Date: Wed, 15 Apr 1998 17:51:49 +0400 (MSD)

From: [email-masked] (Paul Springer)
Sender: [email-masked]
To: [email-masked]
Subject: Some ScaLAPACK performance numbers on Beowulf
Date: Tue, 14 Apr 1998 16:54:15 -0700

Using the ASCI BLAS package on a Beowulf with ScaLAPACK,
I got some pretty reasonable
numbers for multiplying two matrices of double precision numbers.  In the
table below, N is the order of each (square) matrix:

             N     1000     2000     4000     8000
             -------------------------------------
node config|
-----------|
   2x2     |        276      436      396
   4x4     |        285      742     1256     1329

Units are in MFlop/s.  The nodes are 200 MHz Pentium Pro's running Linux.
The BLACS layer under ScaLAPACK was PVM based.  But it had to be modified
to call PVM with the PvmDirectRoute option.  Without this modification
performance figures are cut in half.

Performance drops in the 2x2 configuration probably because the block
size had to be decreased to 100 because of memory limitations.  On
all other runs the block size was N/2 for the 2x2 case and N/4 for the
4x4 case.  Exception:  for the case where N = 8000, the block size also
had to be decreased to 100.

Paul Springer

------------------
Paul Springer
High Performance Computing Group
Jet Propulsion Laboratory

[email-masked]