postgresql-performance using sysbench

[Niki Denev]

On Jan 31, 2008 10:16 PM, Ivan Voras <ivoras at freebsd.org> wrote:
> Niki Denev wrote:
>
> > HZ=1000
> > Time:
> >         239 seconds total
> >         122 seconds of transactions (4 per second)
>
> > What do you think?
>
> This is a very low result :) I don't know your machine or the parameters
> you used with postmark but even FreeBSD on two striped 7.5 kRPM drives
> can achieve ~~ 110 tps (so ~~ 50 for a single drive). In the same
> circumstances and with the right file system - reiserfs in this case -
> Linux can achieve close to 900 tps (170 tps with ext3). This is the kind
> of difference I am talking about. A change of 4 tps to 6 tps is not
> generally useful.
>
>

What settings are you using for postmark?
I ran postmark with default settings, and only changed "size" to "4096
4096000", so it could create
files varying in size from 4K to 3.9M
The machine is dualcore core2duo and has two 10Krpm scsi disks in
geom_mirror and geom_journal on top of them.
I guess that this may be because of geom_journal performance penalty,
having to write everything two times.

Ubench too shows no significant difference, although its not using
disk subsystem at all.

HZ=250
Ubench CPU:   322604
Ubench MEM:   152835
--------------------
Ubench AVG:   237719

HZ=1000
Ubench CPU:   321800
Ubench MEM:   152807
--------------------
Ubench AVG:   237303

Maybe i'll try also "bonnie++"