With the xx50 chips AOD button has green CPU Tweak disabled or green with red circle CPU Tweak enabled

CPU Tweak to my understanding changes cache management

when the Phenom is idling it will power down caches
that's why you take a performance hit going from idle to load because it's ramping up

with CPU Tweak enable it keeps the caches powered up all the time
you get better perfomance but the chip runs hotter

When I try to run at the higher end my overclocks without CPU tweak most of time I"ll lockup or reboot when I start to put a load on the CPU

If run CPU tweak I rarely lock up