There's a $10 difference, and one has free shipping. It'd probably even out after shipping. They both have 2 12V rails with 18amps. Also, if you read on the Cooler Master, it says the +3.3, +5, +12V1 &+12V2 should not exceed 431.5W. The Antec is able to have 500W continuous, supposedly. I don't know much about power supplies though, so you may want someone else to clear this one up for you.