Re: Quad Xeon vs. Dual Itanium

On Mon, 9 Feb 2004, John Gibson wrote:

> Hi, all.
>
> I need to upgrade my dual Xeon PostgreSQL engine.
>
> Assuming similar memory and disk sub-systems, I am considering a Quad
> Xeon system vs. a Dual Itanium for PostgreSQL.  I believe that the
> PostgreSQL code is written for 32 bit and not optimized for the 64 bit
> Itanium cpu.  That makes me think that the Xeon system would be a better
> choice.
>
> Do any of you have thoughts on:
>
> 1. Straight performance capability
> 2. Price/Performance

This really depends on what you'll be doing.  If your data set is very
large, then having a fast drive subsystem and lots of REALLY fast memory
matters more than CPU most of the time.

If you'll be doing lots of CPU intensive stuff, then having four CPUs is
likely to be nice.

It really kinda depends on what you're doing, and how fast the memory
busses / caches are in the two machines.  The CPUs in a well tuned
database server tend to sit near idle mostly, while the drives spin and
the data in memory gets pumped around.

If the Itaniums have twice the memory bandwidth of the Xeons, it might
well be a wash for most loads.

So, what kinda profile are we looking at for your server?