On Fri, 2 Oct 2009, Scott Marlowe wrote:
> On Fri, Oct 2, 2009 at 12:47 AM, alpesh gajbe <alpeshgajbe@gmail.com> wrote:
>
>> We have a Proliant DL585 G5 with 16 cores and 32 GB Ram in the terms of
>> processors we found that buying amd makes much more sense because in the
>> same price we could put more processors
>> on the machine and utilize the multiple cores effectively with PG
>
> I just bought a machine with 12 2.2GHz AMD cores for less than it
> would have cost me for 8 2.26GHz Nehelem cores, so yeah, I've found
> the same thing. And as you go up the price difference keeps getting
> larger.
Huh, apparently I never sent this response...the whole Intel/AMD
comparison at this point really depends on how fast you need any
individual core to be. The Intel i7 systems I was suggesting I like are
expensive, but they are the fastest cores around right now by a good
margin too. If your demands are for lots of cores and you don't care how
much any one of them executes, then sure the AMD systems will save you
quite a bit of cash as suggested above.
But it's not difficult to run into situations with a PostgreSQL server
where you're bottlenecked waiting for something that can only run on one
core at a time. Big reports and COPY are common examples. If that's your
situation, there's no substitute for making the individual cores as fast
as feasible, and there the price premium Intel charges can easily be
worthwhile.
And as I already suggested a while ago, if you're disk bound, you
shouldn't be worrying about optimizing your processor choice very much at
all. Get something cheaper and throw money at spindles and caching
instead.
--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD