Efficiency plays an ever-increasingly important role in modern computers. Particularly with HTPCs designed to run constantly in living rooms, the high level of efficiency of the power supply ensures significantly lower electricity costs at the end of the year.
Overall, the Fortron power supply performed well. In the three load stages of the specification, the unit was constantly at over 84%. The best performance was obtained at below half load, where the efficiency increased to over 88%.
In our fictional system with a 250 watt load, the efficiency remained at a very good 87.7%, but in our low power system it only managed 76.3%.
In standby mode, with no load at all, the power supply only used 440 mW. With a standby load of just 2.5 W (500 mA at 5 V standby voltage) the Fortron converter drew 3.77 W from the socket, which is an efficiency of 65.5%.
The Zen 400 (PPA4000300) from Fortron (FSP) is available for a price of around $150.