Re: Quad Xeon vs. Dual Itanium - Mailing list pgsql-general

From Mark Kirkwood
Subject Re: Quad Xeon vs. Dual Itanium
Date
Msg-id 402D9C6C.2070601@paradise.net.nz
Whole thread Raw
In response to Re: Quad Xeon vs. Dual Itanium  ("Dann Corbit" <DCorbit@connx.com>)
Responses Re: Quad Xeon vs. Dual Itanium  (Mark Kirkwood <markir@paradise.net.nz>)
List pgsql-general
No disagreement from me about the 64-bit *hardware* and *os*...

Now suppose you want to run a Pg database for such a situation.... may
as well compile 32-bit.

Why ? well you *dont* want to set shared_buffers to 20G... in fact 200M
works better -
why ? well your 64-bit os file cache is much more efficient at using
your 24G or RAM than Pg's buffer cache logic is (at the moment anyway).

regards

Mark

Dann Corbit wrote:

>
>Where 64 bits matters (in general -- not restricted to PG database
>systems):
>
>Size of the database is huge (e.g. every toll paid in New Jersey in the
>last 5 years)
>Available memory is huge (e.g. you buy a machine with 24 gigs of ram)
>Data bus bandwidth is huge (e.g. You buy an 8-way Opteron with 40 GB/sec
>bandwidth)
>
>The 32 bit machines cannot compete in these arenas.
>
>
>
>


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