Both systems use a Flex-ATX mini power supply from the Taiwanese manufacturer Achme. The identification plate states that the power supply provides a maximum output of 200 W. According to the AM630B power supply data sheet, the combined load of the 5 V and 3.3 V rails must not exceed 120 W. Not quite so good is the efficiency of the mini voltage converter - the manufacturer quotes 65 percent, which we were able to confirm in our labs. Although the efficiency of a switch-mode power supply is highest when it is under load, a heavy load will create a high build-up of heat. Without revealing too much from our upcoming power supply test: we were pleasantly surprised with the mini power supply. Even under a heavy load (maximum load with a total of 200 W being drawn from the 3.3 V, 5 V, and 12 V rails), the power supply worked fine until it powered down after a few minutes due to overheating. After a short cooling-off period, running again under high load, but not at maximum capacity, was unproblematic.

High heat build-up at low fan speeds: mini power supply from Achme.