Re: FreeBSD: SMP and PostgreSQL

On Thu, 6 Feb 2003, Chris Johnson wrote:

> So to the extent that your performance is limited by kernel "bandwidth"
> moving to FreeBSD 5.x will help.  Chances are you'll be disk IO limited
> long before you get kernel limited, though.


I have to agree with Chris on this one on that the disk subsystem will
likely be a bigger player than switching from 4.X to 5.X

In my case I have a series of daily processes which I keep track or their
time of execution.

I looked at time improvements from going from a single CPU machine to a
dual CPU machine running Raid 5 and then the same machine running Raid 10.

Moving from single CPU to Dual CPU with Raid gave me somewhere in the 20%
improvement. However, when we switched to Raid 0+1 on the same SMP box I
saw performance jump to almost 3 times faster.

Although not exactly an answer to your question, but a testament that
a disk subsystem can be a real differentiator..

Also It realy would be best to wait until the 5.X branch has matured. I
may move my backup machine to 5 to give it a test/trial, but none of my
production machines are moving to it regardless of whether it is going to
be faster or not.