I just hooked up a bunch of resistor loads to the output of this puppy and I was able to pull 20 amps out of my 12 volt rail using the ATXBR01. The power supply is only rated for 10 amps, and it started humming at 15 amps so I didn't keep it there for long. The voltage only dropped to 11.5 volts at a 20 amp load. It stayed around 12 volts with a 10 amp load.
This is from my old AMD 1gig machine's ATX power supply. It is a 300 watt.