Large PostgreSQL servers

Hi,

We are considering to migrate some of our databases to PostgreSQL.

We wonder if someone could give some hardware / configuration specs for
large PostgreSQL installations.
We're interested in:
    - Number of CPUs
    - Memory on the server
    - shared_buffers
    - Size of the database on disk



PS: I have read in "PosgreSQL 9.0 High Performance" that one should not
use more than 8GB for shared_buffers. But Robert Haas and comments say
that one can use a lot more.
http://rhaas.blogspot.com/2012/03/tuning-sharedbuffers-and-walbuffers.html



Regards,

Kjetil Nygård