Strange Performance Problem.

Hi,

I'm developing a application, usign linux, to run in Solaris. I'm usign
perl with DBD::Pg. When I test it on Linux (P4 1.5Ghz + 128 Mb) I' get
more performance than in a two Sun Enterprise 220R, with dual processor
and 2048 Mb RAM. & Solaris 7 Server, the Sun performance is a half than
linux. The main differences are :

In Linux the test are only in machine (Perl 5.6.0 + APP + PGSQL 7.1.2).
the PGSLQ parameter are:
sort_mem = 8192
shared_buffers = 1024
fsync = false

In Solaris I've have a machine for APP (Perl 5.6.1) an another for
PGSQL 7.1.2). usign a tcp network: The PGSQL parameters are:
sort_mem = 65536
shared_buffers =3040
fsync = true
max connections = 512

It's postgresql more optimized for linux?
Must have Solaris fsync = false ?
or simply I am crazy :-))))?