Solaris Performance (Again)

This is a well-worn thread title - apologies, but these results seemed
interesting, and hopefully useful in the quest to get better performance
on Solaris:

I was curious to see if the rather uninspiring pgbench performance
obtained from a Sun 280R (see General: ATA Disks and RAID controllers
for database servers) could be improved if more time was spent
tuning.

With the help of a fellow workmate who is a bit of a Solaris guy, we
decided to have a go.

The major performance killer appeared to be mounting the filesystem with
the logging option. The next most significant seemed to be the choice of
sync_method for Pg - the default (open_datasync), which we initially
thought should be the best - appears noticeably slower than fdatasync.

We also tried changing some of the tuneable filesystem options using
tunefs - without any measurable effect.

Are Pg/Solaris folks running with logging on and sync_method default out
there ? - or have most of you been through this already ?

Pgbench Results (no. clients and transactions/s ) :

Setup 1: filesystem mounted with logging

No. tps
-----------
1 17
2 17
4 22
8 22
16 28
32 32
64 37

Setup 2: filesystem mounted without logging

No. tps
-----------
1 48
2 55
4 57
8 62
16 65
32 82
64 95

Setup 3 : filesystem mounted without logging, Pg sync_method = fdatasync

No. tps
-----------
1 89
2 94
4 95
8 93
16 99
32 115
64 122

Note : The Pgbench runs were conducted using -s 10 and -t 1000 -c 1->64,
2 - 3 runs of each setup were performed (averaged figures shown).

Mark