What is all this discussion about PSU efficiency? FACTS * Better brand = better PSU = better efficiency. In most cases. * If you have two PSU's of the same brand and line, and one can produce 500 watt and the other 1000 watt, the 1000 watt will be more efficient in pretty much every case. Just prepare to pay a premium price for a 1000 watt capable PSU, which is why it's recommended to buy the lesser PSU if it runs fine too. If you got money to spare, buy the better one. So Dutchman, you're wrong about the efficiency.