Re: Quad Xeon vs. Dual Itanium

> -----Original Message-----
> From: Mark Kirkwood [mailto:markir(at)paradise(dot)net(dot)nz]
> Sent: Friday, February 13, 2004 5:30 PM
> To: Andrew Sullivan
> Cc: pgsql-general(at)postgresql(dot)org
> Subject: Re: [GENERAL] Quad Xeon vs. Dual Itanium
>
>
> Wouldn't you only care about 64-bit Postgres if you wanted to make
> shared_buffers bigger than 4G?
>
> Various other posters have commented about the sweet-spot for
> shared_buffers being ~ 100-200M (or thereabouts).
>
> So it seems to me that there is nothing to be gained using a 64-bit
> binary with the current or previous Pg releases. However,
> with the new
> cache replacement system being used in 7.5devel, the
> situation *may* be
> different (wonder if anyone has tried this out yet?).

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.