Have you set the -Xms and -Xmx options of your Java virtual machine to match your 1G Ram ? The defaults are normally very low values.
Watch out for database connection problems as your txRate increases (ecperf has about 8 clients per txRate), Postgres has a default of only 32 connections, this should be increased.
Also seems like the jboss default for the max-pools-size for datasource connections is 20. Add a <max-pool-size>100</max-pool-size> with your choice of connection pool size (not necesarily 100) to postgres-ds.xml in the deploy directory.
jboss 3.2.1 seems to be better than jboss 3.0.6.
we're getting a txRate of almost 20 on a 1GB dual athlon 2100MP
Thanks for your help! I finally got it working ...
I have set most of those parameters before, except the -Xms option. Do you know any reason, what makes the difference between those two approaches? I think, the vm should be able to reallocate as much memory until the maximum value (mx) is reached - independent from the initial value! Am I wrong? Why?
I have also been surprised by the fact that I wasn't able to set a larger value for -Xmx that 1900M (or something like that) on a machine having 8GB RAM!