On Thursday 14 September 2006 09:53, Mark Abraham wrote: > Qiao Baofu wrote: > > Hi, > > > > Thanks. I have test different cpus. Our institute has two clusters: one > > is each node has 4 cpu (A), one is one node has only 1 cpu (B). I made > > different tests on the two clusters and my local computer using the same > > system. See the following result: > > > > A (For 1 hour) > > # of cpus ; MD steps > > 4 finished (200000steps for 26:21) > > 8 finished (200000steps for 40:57) > > 12 87950 > > 20 42749 > > 44 5962 !!!!! > > B (For 1 hour) > > # of cpu ; MD steps > > 1 156991 for 56:12 > > 2 179820 > > 3 200,000 for 54:20 > > 4 200,000 for 51:12 > > c. Local(single cpu), 200000 steps For 1h52:38 > > > > One can see that > > 1. On cluster A, one nodes(4 cpu) is just as 4 times fast as my local > > computer. > > 2. More than one nodes will decrease the performancs the gromacs, > > 3. On cluster B, the more cpu used, the faster gromacs runs. But the > > difference of speed is not apparent. > > 4. Cluster B with 4 cpus is slow as half as that Cluster A with 1 node > > (4 cpus) > > > > I wonder if anyone can tell the bottlenack: the hardware on the cluster > > or gromacs? > > Probably your interconnects between nodes are using carrier pigeons or > something :-) I expect that 1 cpu on machine A will require around four > times as long as 1 4-cpu node, which you can presumably test for yourself. > > For next time, if you want to compare hardware like this, either use the > same length of time or the same number of MD steps for all of your runs. > Also when reporting runtimes, make it clear whether you are reporting > walltime or some time * number_of_cpus, etc. :-)
Search the mailing list i have post several times benchmark results for different systems with standard benchmark suite. http://www.gromacs.org/pipermail/gmx-developers/2006-January/001473.html > > Mark > _______________________________________________ > gmx-users mailing list gmx-users@gromacs.org > http://www.gromacs.org/mailman/listinfo/gmx-users > Please don't post (un)subscribe requests to the list. Use the > www interface or send it to [EMAIL PROTECTED] > Can't post? Read http://www.gromacs.org/mailing_lists/users.php Greetings, Florian -- ------------------------------------------------------------------------------- Florian Haberl Computer-Chemie-Centrum Universitaet Erlangen/ Nuernberg Naegelsbachstr 25 D-91052 Erlangen Telephone: +49(0) − 9131 − 85 26581 Mailto: florian.haberl AT chemie.uni-erlangen.de ------------------------------------------------------------------------------- _______________________________________________ gmx-users mailing list gmx-users@gromacs.org http://www.gromacs.org/mailman/listinfo/gmx-users Please don't post (un)subscribe requests to the list. Use the www interface or send it to [EMAIL PROTECTED] Can't post? Read http://www.gromacs.org/mailing_lists/users.php