Re: FreeBSD: SMP and PostgreSQL

On Sun, 9 Feb 2003, Francisco J Reyes wrote:

> 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.

Thanks for this info.  I've just started playing with FreeBSD 5.0, and as 
my BSD experience is rather dated, I figured I'd just learn BSD5.0 while 
it matures and we'll both be ready to deploy in a few more months. :-)

I've got to say it looks from this report as if BSD has a better disk 
subsystem than Linux in this regard, because there I was never able to get 
much better performance from multi-layered RAID than I could with 
whichever was the "slowest" layer method mixed in.  I.e. if RAID1 was 
limited to X performance, and RAID0 was capable of 4X, then going to RAID 
1+0 or 0+1 would only be X fast.

Just to make it fun, I'm playing with it on an old Dual CPU PPro box 
that'll dual boot linux for comparison.

Any tips for a newbie besides reading the online docs (which I'm in the 
middle of) ???