400 Watt Class
Aerocool Aero-420P4 // Aeropower II
Aerocool's high-quality power supply unit is convincing: In the test the Aero-420P4 // Aeropower II operated with absolute stability. With a maximum power of 455 watts it also offers sufficient power reserves.
The fan rpm can be controlled with a three-way switch.
The user can change the fan rpm with a three-way switch on the back: Low, middle and automatic. But it earns minus points for the volume level during operation: 38.5 dB(A) to 46 dB(A) on the A setting is too loud. Although 30 dB(A) on the L setting is a good value, heat problems can occur at this setting when higher power is required.
Positive : the overload protection, which shuts the power supply unit off promptly when it is overloaded.
Unusual : the design. Three green acrylic windows allow a look into the interior of the shiny case; two fans with green LEDs illuminate the goings-on inside the case.
Our test device specifies an input power of 195 to 250 volts. But Aerocool also offers corresponding models for input power ranges of 95-132 volts or 88-264 volts (with active PFC).