[mpich-discuss] Why is my quad core slower than cluster

[zach]

Following up on these suggestions and info queries...
(Thanks for the help!)

I noticed my home pc processor is a
Core2 Quad CPU Q6600  @ 2.40GHz (Kentsfield)
whereas the cluster Xeon is 3.20GHz.
I don't think this is causing the degree of 3 in speed.

compiler is gcc on home pc and cluster.

same optimization option for both systems
yes cpuinfo and meminfo show the right #cpus and mem

mpich is different versions i have discovered.

on cluster (faster one),
MPICH Version:    	1.2.7p1
MPICH Release date:	$Date: 2005/11/04 11:54:51$
MPICH Patches applied:	none
MPICH configure: 	--prefix=/opt/mpich/intel --enable-sharedlib
--with-romio --enable-f90modules -c++=icpc -cc=icc -fc=ifort
-f90=ifort
MPICH Device:    	ch_p4

on home pc (the slug),
MPICH2 Version:    	1.0.7
MPICH2 Release date:	Unknown, built on Tue Jul  8 19:28:07 CDT 2008
MPICH2 Device:    	ch3:nemesis
MPICH2 configure: 	--prefix=/home/code/mpich --with-device=ch3:nemesis
MPICH2 CC: 	gcc  -O2
MPICH2 CXX: 	c++  -O2
MPICH2 F77: 	
MPICH2 F90: 	

on the cluster I have been compiling with mpiCC and on the home pc with mpicxx.

kernel on home pc:
Linux myPC 2.6.24-18-generic #1 SMP Wed May 28 19:28:38 UTC 2008
x86_64 GNU/Linux

I am using ubuntu hardy and did not use 'sudo' during installation of
mpich2 (not logged in as superuser) -don't know if this matters.

zach