Re: most bang for buck with ~ $20,000 - Mailing list pgsql-performance

Great info, which vendor were you looking at for these Opterons? I am goign
to be purchasing 2 of these. :) I do need 24/7 reliability.

On Tue, Aug 08, 2006 at 05:08:29PM -0500, Scott Marlowe wrote:
> On Tue, 2006-08-08 at 15:43, Kenji Morishige wrote:
> > I've asked for some help here a few months ago and got some really helpfull
> > answers regarding RAID controllers and server configuration.  Up until
> > recently I've been running PostgreSQL on a two year old Dual Xeon 3.06Ghz
> > machine with a single channel RAID controller (previously Adaptec 2200S, but
> > now changed to LSI MegaRAID). The 2U unit is from a generic vendor using what
> > I believe is a SuperMicro motherboard.  In the last week after upgrading the
> > RAID controller, the machine has had disk failure and some other issues. I
> > would like to build a very reliable dedicated postgreSQL server that has the
> > ultimate possible performance and reliabily for around $20,000.  The data set
> > size is only currently about 4GB, but is increasing by approximately 50MB
> > daily.  The server also requires about 500 connections and I have been
> > monitoring about 100-200 queries per second at the moment.  I am planning to
> > run FreeBSD 6.1 if possible, but I am open to any other suggestions if it
> > improves performance.
>
> This really depends on your usage patterns.
>
> OLAP or OLTP workloads?  Do you need 24/7 reliability and therefore a
> two machine setup?  There's a lot of variety in load.
>
> Generally, you spend your money on disks, then memory, then CPU, in that
> order.
>
> Look at the Areca cards, they've come highly recommended here.  Look at
> LOTS of drives.  Given the size of your db, you can go with LOTS of
> smaller drives and get good performance.  If you can find a good box to
> hold 12 to 16 drives and fill it with 37 gig 15k RPM drives, you'll have
> lots of storage, even in RAID 1+0 config.  That's aiming at
> transactional throughput.
>
> Toss as much memory as is reasonably affordable at it.  That's normally
> in the 4 to 8 gig range.  After that things start to get expensive fast.
>
> Multiple - dual core CPUs are a good idea.  Opterons seem to be better
> "data pumps" with large memory and >2 CPUs than Intels right now.
> Better to have a 2xdual core opteron with slower processors than a
> single dual core or dual single core CPU(s) with a faster clock speed.
> As long as the memory access is equivalent, the more CPUs the better in
> Opterons, where their interconnect speed increases as you increase the
> number of CPUs.  Intel Xeons are the opposite.  Better with fewer faster
> CPUs / cores.
>
> I just ran through a configurator on a site selling quad dual core
> opteron servers.  8 Seagate cheetah 15k rpm drives, 8 gig ram, and the
> slowest (1.8 GHz) AMD dual core CPUs (4 of them) for 8 cores, came out
> to $13,500 or so.
>
> I'd take the other $7.5 grand and buy a backup server that can old as
> much but isn't quite as beefy and set up slony to have a live hot spare
> sitting ready.  Oh, and maybe to buy some spare parts to sit in the desk
> drawer in case things break.