Postgresql works too slow

Hello.

I'm trying to restore my database from dump in several parrallel processes, but restore process works too slow.
Number of rows about 100 000 000,
RAM: 8192M
CPU: Ultra Sparc 3
Number of CPU: 4
OS: SunOS sun 5.8
RDBMS: PostgreSQL 8.0

====================            prstat info            ====================

   PID USERNAME  SIZE   RSS STATE  PRI NICE      TIME  CPU PROCESS/NLWP
 14231 postgres   41M   37M sleep   58    0   0:00.01 0.2% postgres/1
 14136 postgres   41M   37M sleep   58    0   0:00.03 0.2% postgres/1
 14211 postgres   41M   37M sleep   58    0   0:00.01 0.2% postgres/1
 14270 postgres   41M   37M sleep   58    0   0:00.00 0.2% postgres/1
 13767 postgres   41M   37M sleep   58    0   0:00.18 0.2% postgres/1
 13684 postgres   41M   36M sleep   58    0   0:00.14 0.2% postgres/1

 NPROC USERNAME  SIZE   RSS MEMORY      TIME  CPU
    74 root      272M  191M   2.3%   0:26.29  24%
   124 postgres 1520M 1306M    16%   0:03.05 5.0%


How to encrease postgresql speed? Why postgres took only 5.0% of CPU time?

Nurlan Mukhanov