Re: Server specs to run PostgreSQL

On Tue, 2007-05-08 at 14:04, MaRCeLO PeReiRA wrote:
> Hi there,
>
> Actually my PostgreSQL server is running on a Athlon
> XP 1800+, 512Mb RAM, IDE Disks, 10/100 netcard.
>
> I would like to buy a new server, could you please
> give me some information about the specs??
>
> Is it important to have a Dual (or even Quad)
> processor??? Will PostgreSQL use them??
>
> What about memory??? How much???
>
> SCSI Disks and 10/100/1000 netcards, it's ok!! No
> doubt!
>
> It's a medium use server, about 3000 transactions/day.

Assuming that most of your transactions happen from 9-5, then that's
about 6 transactions per second. Assuming these are mostly lightweight
transaction, you'll be needing a pentium 100 with 64 megs of ram. :)

Seriously though, the hardware you need / want REALLY depends on your
usage patterns. Are you doing a lot of CPU intensive stuff, where
having more CPUs or faster / more memory would help, or are you mostly
I/O bound, and in need of a faster disk subsystem.

Dual CPUs are almost always a good thing, as there's enough going on
other than pgsql (the OS and all its processes) that having a second CPU
can make a machine noticeably more responsive. After that, it's hard to
say. PostgreSQL itself can only use 1 cpu per connection max, plus one
for things like th background writer or periodic vacuuming. So, if
you've only got one user at a time ever hitting your DB, then multiple
CPUs wouldn't help.

Here's what I recommend for a db server:

Lots of memory
2 CPUs (more if needed, maybe dual core x 2)
battery backed caching RAID controller. Look at Areca, 3Ware/Escalade,
and LSI
Lots of hard disks for said controller
fast, efficient NIC. Better to spend a little more in a quality NIC
with a low CPU overhead.