Yes, this is true, but, the machine is an AMD 2200+ and only has one hard
drive inside.
Right next door is an AMD 2100+ which has about 4 hard drives inside.
The 2100+ machine raises the room temp about 3-4 degrees F -- which is
bareable. The 2200+ machine raises the room temp about 15-20 degrees F.
Since they both have simmilar hard ware configs, one would assume that they
would put off almost equal levels of heat. Beyond this, the inside of the
case always remains relatively cool (on both of them). This is what led me
to this assumption -- as the only main difference between the two is the
brand of power supply.
Looks like I have some dissection to be doing this weekend.