we benchmarked a (P4 3.2 HT, 4GB ram, postgresql, redhat 9) with the following configs HT disabled, smp kernel; HT enabled, smp kernel; HT disabled, non-smp kernel; HT enabled, non-smp kernel;
and the fastest is the HT disabled non-smp kernel. we saw two cpus when HT was on in the smp kernel. postgresql was using both cpus. but performance was a slightly less. my *guess* is that HT is fake-smp. and the slowdown is caused by 1) the SMPing (routines, syncs, etc) overhead in the OS level and 2) the P4 overhead caused by pretending to be 2 cpus other things you want to know about the benchmark: *no swapping *we run the tests at least 3 times *the postgresql data directory was 2.6gb (data, indexes, etc) *"time" was used. system, user and sys time were recorded. *we watched all the results/outputs of the reports in tty1, so display I/O time should be insignificant -- Philippine Linux Users' Group (PLUG) Mailing List [EMAIL PROTECTED] (#PLUG @ irc.free.net.ph) Official Website: http://plug.linux.org.ph Searchable Archives: http://marc.free.net.ph . To leave, go to http://lists.q-linux.com/mailman/listinfo/plug . Are you a Linux newbie? To join the newbie list, go to http://lists.q-linux.com/mailman/listinfo/ph-linux-newbie
