Load Tests

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. Then we tried to pull even more power from this unit and the results for this test is on next page.

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 two power supply ATX12V connectors to it. So it was connected to the power supply +12V1 bus. The +12V1 input from our load tester, on the other hand, was connected to both +12V1 (main motherboard connector) and +12V2 (video card and peripheral plugs) rails.

Input	Test 1	Test 2	Test 3	Test 4	Test 5
+12V1	4 A (48 W)	8 A (96 W)	12 A (144 W)	15 A (180 W)	21 A (252 W)
+12V2	4 A (48 W)	8 A (96 W)	11 A (132 W)	15 A (180 W)	16.5 (198 W)
+5V	1 A (5 W)	2 A (10 W)	4 A (20 W)	6 A (30 W)	8 A (40 W)
+3.3 V	1 A (3.3 W)	2 A (6.6 W)	4 A (13.2 W)	6 A (19.8 W)	8 A (26.4 W)
+5VSB	1 A (5 W)	1 A (5 W)	1.5 A (7.5 W)	2 A (10 W)	2.5 A (12.5 W)
-12 V	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)
Total	118. W	224.5 W	329. W	432.8 W	542.4 W
% Max Load	22.5%	42.8%	62.7%	82.4%	103.3%
Room Temp.	47.3º C	46.8º C	48.4º C	48.4º C	50.0º C
PSU Temp.	51.7º C	51.3º C	51.3º C	51.8º C	53.9º C
Voltage Stability	Pass	Pass	Pass	Pass	Pass
Ripple and Noise	Pass	Pass	Pass	Pass	Pass
AC Power	133 W	249 W	370 W	496 W	635 W
Efficiency	88.7%	90.2%	88.9%	87.3%	85.4%
Final Result	Pass	Pass	Pass	Pass	Pass

What a power supply! It could not only deliver its labeled power at 50º C but it could also maintain efficiency always above 85%, peaking 90% on test number two (40% load, 225 W). This is the first time we’ve seen a power supply peaking more than 90% efficiency. This unit broke our efficiency record set before by Antec EarthWatts 500 W and Corsair VX450W.

Voltage regulation was also 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.

During all tests ripple and noise levels were within specs, but other good mainstream power supplies we’ve reviewed like Antec EarthWatts 500 W and Corsair VX450W achieved far better values on the +12 V outputs (below 20 mV on +12 V outputs, while on the reviewed power supply noise level at +12 V outputs were around  50 mV during test number five). But the results were not bad at all: 50.2 mV at +12V1 input from our load tester, 51.8 mV at +12V2 input from our load tester, 13.2 mV at +5 V and 9.4 mV at +3.3 V. 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.

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Figure 16: Noise level at +12V1 input from our load tester with the reviewed unit delivering 542 W.

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Figure 17: Noise level at +12V2 input from our load tester with the reviewed unit delivering 542 W.

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Figure 18: Noise level at +5 V input from our load tester with the reviewed unit delivering 542 W.

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