Surprizing performances for Postgres on Centrino

Hi,
These last two days, I have some troubles with a very strange phenomena:
I have a 400 Mb database and a stored procedure written in perl which
call 14 millions times spi_exec_query (thanks to Tom to fix the memory
leak ;-) ).
On my laptop whith Centrino 1.6 GHz, 512 Mb RAM,
- it is solved in 1h50' for Linux 2.6
- it is solved in 1h37' for WXP Professionnal ( WXP better
tan Linux ;-) )
On a Desktop with PIV 2.8 GHz,
- it is solved in 3h30 for W2K
On a Desktop with PIV 1.8 GHz, two disks with data and index's on each disk
- it is solved in 4h for W2K

I test CPU, memory performance on my laptop and it seems that the
performances are not perfect except for one single  test: String sort.

So, it seems that for my application (database in memory, 14 millions
of very small requests), Centrino (aka Pentium M) has a build-in
hardware to boost Postgres performance :-)
Any experience to confirm this fact ?
Some tips to speed up Postgres  on non-Centrino processors ?

-- 
Jean-Max Reymond
CKR Solutions Open Source
Nice France
http://www.ckr-solutions.com