We made several tests with this power supply as described in the article Hardware Secrets Power Supply Test Methodology.

First we tested this power supply with five different loads patterns, trying to pull around 20%, 40%, 60%, 80% and 100% of its labeled maximum capacity (under “% Max Load” we list the actual percentage that was used), watching how the reviewed unit behaved under each load. On the table below we list the load patterns we used and the results for each load.

For the 100% load test we used two patterns. On the first one, test number five, we respected the maximum combined limit for the two +12 V rails printed on the power supply label (312 W). In order to respect this limit, however, we were testing the power supply with more current on the +5 V and +3.3 V lines than we wanted. So we included a sixth pattern also pulling 460 W from the reviewed unit but pulling more current from +12 V and less current from +5 V and +3.3 V.

If you add all the powers listed for each test you may find a value different from what posted under “Total” below. Since each output can have a slight variation (e.g. +5 V output working at 5.10 V) the actual total amount of power being delivered is slightly different from the calculated value. On “Total” row we are using the real amount of power being delivered, as measured by our load tester.

+12V2 is the second +12V input from our load tester and during our tests we connected the power supply ATX12V connector to it. Since the ATX12V connector is the only device connected to the power supply +12V2 rail, on this test +12V1 and +12V2 inputs from our load tester were really connected to +12V1 and +12V2 rails.

This power supply failed to deliver 460 W. The funny thing was that respecting the maximum combined power for the two +12 V rails as printed on the unit’s label (test five) the power supply wouldn’t turn on, as its over power protection entered in action, but pulling 460 W not respecting this information (test six) it turned on, but ripple was thru the roof (220 mV). We tested to see the maximum power this unit could deliver and the results are on next page.

Efficiency was good (i.e. above 80%) when we pulled between 40% and 60% of the power supply maximum labeled power (i.e. between 185 W and 280 W), dropping below 80% on tests one (97 W) and four (370 W). These results are not bad for a USD 40 power supply, especially when we think that other low-end units that we’ve reviewed like Thermaltake Purepower 430 W NP and Seventeam ST-420BKV achieved values far below those.

On the other hand voltage regulation was outstanding and during all our tests all outputs were within 3% of their nominal voltages – ATX specification defines that all outputs must be within 5% of their nominal voltages (10% for -12 V) –, including -12 V, which usually is not close to its nominal value (as we showed before this unit uses a voltage regulator integrated circuit for this output, and this explains its good performance).

During all tests this power supply achieved ripple and noise levels within specs, but other good mainstream power supplies we’ve reviewed like Antec EarthWatts 500 W and Corsair VX450W achieved far better values here (below 20 mV on +12 V outputs, while on the reviewed power supply noise level at +12 V outputs were between 54 mV and 59 mV during test number four). Just to remember, all values are peak-to-peak voltages and the maximum allowed set by ATX standard is 120 mV for +12 V and 50 mV for +5 V and +3.3 V.

Let’s now see how much power we could pull from this unit keeping it working inside ATX specs.