Fortron/FSP Zen 400 (Continued)
On the rear of the power supply you’ll find the IEC socket and a blue illuminated main switch. The latter is of particular importance, as a user operating a passive power supply cannot hear whether or not it is switched on. There are no other indicators showing the operational status of the unit.
The power supply is a full range unit that can be operated on a voltage ranging between 110 V and 240 V. There is no need to manually switch between the voltage ranges.
The output of the power supply is 400 watts, and 560 watt peaks are possible for short periods of time. The combined performance of the 3.3 V and 5 V rails is a maximum of 130 watts.
During use, the power supply makes its presence known by a high-pitched, high-frequency noise that occurs most often when under heavy use. Up to a load of approximately 250 watts this noise can hardly be heard, but the higher the load gets, the louder the noise. This is a very annoying noise that detracts from the "silent PC" concept.
With no additional ventilation, constant operation under full load at 400 watts is not possible. The power supply switches itself off due to overheating after approximately two hours. A level of 300 watts, however, can be maintained permanently. A minimal movement of air in the computer case—such as a slowly rotating 120 mm fan—enables the device to be operated permanently at high load.
The test with the D201GLY2 board from Intel was not a problem—this kind of mini ITX board often causes problems with power supplies.