Hi Scott, the controller is a HP i410 running 3x300GB SAS 15K / Raid 5 Mit freundlichen Grüßen Felix Schubert Von meinem iPhone gesendet :-) Am 25.08.2012 um 14:42 schrieb Scott Marlowe <scott.marlowe@xxxxxxxxx>: > On Sat, Aug 25, 2012 at 6:07 AM, Felix Schubert <input@xxxxxxxxx> wrote: >> Hello List, >> >> I've got a system on a customers location which has a XEON E5504 @ 2.00GHz Processor (HP Proliant) >> >> It's postgres 8.4 on a Debian Squeeze System running with 8GB of ram: >> >> The Postgres Performance on this system measured with pgbench is very poor: >> >> transaction type: TPC-B (sort of) >> scaling factor: 1 >> query mode: simple >> number of clients: 40 >> number of transactions per client: 100 >> number of transactions actually processed: 4000/4000 >> tps = 158.283272 (including connections establishing) >> tps = 158.788545 (excluding connections establishing) > > For a single thread on a 10k RPM drive the maximum number of times per > second you can write and get a proper fsync back is 166. This is > quite close to that theoretical max. > >> The same database on a Core i7 CPU 920 @ 2.67GHz, 8 cores with 8GB RAM same distro and Postgresql Version is much faster: >> >> transaction type: TPC-B (sort of) >> scaling factor: 1 >> query mode: simple >> number of clients: 40 >> number of transactions per client: 100 >> number of transactions actually processed: 4000/4000 >> tps = 1040.534002 (including connections establishing) >> tps = 1065.215134 (excluding connections establishing) > > This is much faster than the theoretical limit of a single 10k RPM > drive obeying fsync. > > I'll ignore the rest of your post where you get 53 tps after > optimization. The important thing you forgot to mention was your > drive subsystem here. I'm gonna take a wild guess that they are both > on a single drive and that the older machine is using an older SATA or > PATA interface HD that is lying about fsync, and the new machine is > using a 10k RPM drive that is not lying about fsync and you are > getting a proper ~150 tps from it. > > So, what kind of IO subsystems you got in those things? > > > -- > Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
