Running RGB led array from 3.3v on ATX PSU?

Hello all!

I recently build an led panel consisting of 32 rgb smd leds each with their own current limiting resistors (150 ohm, 1206, closely packed). I'm running it from the 5v line on my atx psu, but the resistors get a bit warm for my liking (its only 50 deg C, but its in an enclosed space that I really don't want that heat in).

The psu info plate says it can take 21A on the 3.3V line, and my circuit draws 1.5A (will be 3A as there will soon be two boards). My question is, is that 63-odd watts on the 3.3V line shared with the other voltages, or can I safely use the 3A that I need to run the led array? These led's run on 3v Blue, 3v Green, and 2V red, so I can greatly reduce the power dissipated, and therefore the heat created.


Thanks for listening,
Neal

The power supply has a total max power, in addition to a max power (current) on each output. The total is usually much less than the sum of the parts. As long as you exceed NEITHER the limit on any particular output NOR the max total, you should be good.