RE: How to convert an ATX power supply to rc use
I would say it really dpends on your power supply. For most I think a single 10w is a bit weak, but if it works then it works =) I personally have four 1 ohm 10 watt resistors in series for a total of a 4 watt load, and a total of 6.63w power dissipation, or 1.65w per wirewound, and that brings me up to 12.2v
The main thing to remember is TPD or Thermal Power Dissipation. The resistors are designed with a 10w max load so you don't want to go over that. Above a certain point they will need to be sinked or they will get really hot. How you figure that for your 5v rail is 26.5225 divided by the # of watts you have, so if you want to have 2 watts resistance then you would have to dissapate 13.26w of power, if you only had 1 resistor it would cook, and if you had 2 of them without sinking them, they would get very hot.
hopefully that answers your q