possible improvement between G4 and G5

Hi,

We have got a G5  64-bit processor to replace an old G4 32-bit
processor.  Given everything
else equal, should we see a big improvement on PG's performance?

The other question I have is that, when I tried different size for
shared_buffer ( i used 10,000,
1,000, 528, 256) and Max connections=32, it gives me error when I tried
to start PG using
pg_ctl start as postgres. It kept saying this is bigger than the system
Shared Memory.  So finally
I started PG using SystemStarter start PostgreSQL and it seems starting
OK. Any idea?


Thanks a lot!

Qing Zhao