*All voltages were read from the Motherboard BIOS.

Listed Voltages	Lower Voltage	Upper Voltage	Jitter
+3.3V	3.47v	3.47v	0.04v
+5.0V	4.92v	4.98v	0.06v
+12V	13.36v	13.50v	0.14v
-12V	12.00v	12.00v	0.00v
-5.0V	5.00v	5.00v	0.00v
+5.0Vsb	5.00v	5.00v	0.00v

The good new is that the AOpen Silent Power AO400-12AHN showed barely any fluctuation in voltage during testing. The bad news is that the +12V rail was a little on the high side, though not nearly enough to cause problems. If anything, this might be a positive attribute for stability, but it's worth noting.

Seasonic Load Tests	Source: Seasonic

When looking at the Seasonic Power Supply test results we see two values, wattage and volt-amps. Since it might not be clear what they measure, here's a brief overview.

The volt-amp (VA) value is how much real power is being consumed by the power supply being tested to provide the wattage (W) value. The higher the VA value is, the more electricity is being used by the power supply. Because no electrical device is 100% efficient, there will always be some loss when converting AC to DC. The closer the volt-amps and wattage figures are to each other, the more efficient a power supply is. This is called the Power Factor: wattage / volt-amps = PF.

Since we're testing with a 120W dummy load, the load on the power supply (wattage) should be as close to this figure as possible. Anything above this load in apparent power describes the overhead and wasted energy (given off as heat) for the particular power supply being tested.

For the unloaded tests, the wattage and volt-amp figures should be as close as possible to one another. The lower the figures are, the less power is being used.

Seasonic Load Tests
Power Supply	Wattage	Test	Load	Unloaded
Seasonic SuperTornado	400 W	Active Power	177 W	6 W
		Apparent Power	182 VA	7 VA
Vantec iON2	350 W	Active Power	192 W	10 W
		Apparent Power	277 VA	21 VA
Antec TruePower 330	330 W	Active Power	195 W	22 W
		Apparent Power	289 VA	38 VA
Ultra X-Connect Green UV 500W	500 W	Active Power	193W	22 W
		Apparent Power	307 VA	40 VA
AOpen Silent Power AO400-12AHN	400W	Active Power	179W	9 W
		Apparent Power	275 VA	18 VA

The AOpen Silent Power AO400-12AHN shows decent numbers here, though we'd like to have seen less of a discrepancy between the load W and VA numbers. This PSU is economical on power when its not loaded though, which is a good sign of quality. All in all, this power supply showed average performance in this power efficiency test.

A good all around power supply