> My supply sure looks linear, so I cranked it up to +12VDC.
> Now, at 32C
> ambient temperature, the supply seems cooler to the touch,
> and the firewall
> is working without a hitch. Maybe I won't have to spring for
> the better
> one after all.
Any electrical device has a wattage that it requires to operate.
Wattage is Volts * Amps.
As the recommended voltage goes down, the amperage goes up. Amperage
causes excessive heat and can also fry things very quickly.
Running a device at the recommended voltage is the best way to go. It
will run cooler and more efficiently.