CPU usage is low/benchmark time

[freaker_ca]

i'm wondering why only 50% of my cpu is used when rendering. i have multithreaded checked in the preferences. what kind of reading do the rest of you folks get? how can i boost the cpu usage?

for benchmarking purposes i'm rendering the ies_sun max file found here: http://www.jeffpatton.net/Max6/index.html

please post your render times and let me know what percentage of your cpu usage you get (task manager, performance)

my render time was 1 minute, 59 seconds
max version=6
CPU=dual opteron 280 dual-core
RAM=2gigs ddr400
MOBO=asus k8n-dl
Vid card=radeo saphire x800xl 512 mb

[freaker_ca]

a buddies Intel Pentium Northwood 4 3.0GHz CPU rendered that file in 4:29.