My ASUS M3A78-CM motherboard instructions state that I need 24A power @ 3.3V, 24A @ 5V, and 17A at 12V. I have a Corsair CMPSU-400CX 400W supply but at 20A, 20A, and 30A, respectively. Do I need a new power supply or can I get away with my current supply despite the ASUS specs?
These figures are usually based on a fully populated board theoretically.
That means all usb's, ram slots, card slots etc. Its intereresting to note that they mentioned anything at all, I can't remember such a listing in any manual.
I have every reason to believe your power supply will work fine, particularly the one you have.