Multi Procerssor

Maybe late to ask this question - but - does PG benefit from multi
processor? Is it dependant on the OS? And which OS' are most tuned for
this purpose?

As always thanks in advance!

From FAQ:

       We handle each user connection by creating a Unix process.
      Backend processes share data buffers and locking information.
      With multiple CPU's, multiple backends can easily run on
      different CPU's.<BR>
-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Maybe late to ask this question - but - does PG benefit from multi
processor?

Though it's not threaded, multiple backends will use multiple processors .

Is it dependant on the OS?

Yes. The OS has to allow use of the second (or third or fourth) processor.
Most modern Unix-like OSes will have this feature... OpenBSD is the only one
I can think of off the top of my head that doesn't have SMP support.

And which OS' are most tuned for this purpose?

Tuned for SMP? Well, different OS's handle that in many different ways so
that's a question which requires a pretty long answer to cover all the
possibilities..

I use FreeBSD and Linux (though mainly FreeBSD) on my SMP boxes and both do
a fine job.

-Mitch