
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.
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.
+12V1 and +12V2 are the two independent +12V inputs from our load tester and during our tests the +12V1 input was connected to the power supply +12V1 (main motherboard connector and peripheral power connectors) and +12V3 (video card power connector) rails at the same time, while the +12V2 input was connected to the power supply +12V2 rail (EPS12V connector).
Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
+12V1 | 5 A (60 W) | 10 A (120 W) | 14 A (168 W) | 19 A (228 W) | 26.5 A (318 W) |
+12V2 | 4.5 A (54 W) | 10 A (120 W) | 14 A (168 W) | 19 A (228 W) | 22 A (264 W) |
+5V | 1 A (5 W) | 2 A (10 W) | 4 A (20 W) | 5 A (25 W) | 6 A (30 W) |
+3.3 V | 1 A (3.3 W) | 2 A (6.6 W) | 4 A (13.2 W) | 5 A (16.5 W) | 6 A (19.8 W) |
+5VSB | 1 A (5 W) | 1.5 A (7.5 W) | 2 A (10 W) | 2.5 A (12.5 W) | 3 A (15 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 | 134.2 W | 271.4 W | 386.3 W | 516.4 W | 652.9 W |
% Max Load | 20.6% | 41.8% | 59.4% | 79.4% | 100.4% |
Room Temp. | 49.8º C | 48.4º C | 49.8º C | 46.8º C | 49.3º C |
PSU Temp. | 49.6º C | 50.1º C | 51.4º C | 48.9º C | 53.5º C |
Voltage Stability | Pass | Pass | Pass | Pass | Pass |
Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
AC Power (1) | 153 W | 300 W | 429 W | 578 W | 748 W |
Efficiency (1) | 87.7% | 90.5% | 90.0% | 89.3% | 87.3% |
| AC Power (2) | 163.0 W | 315.3 W | 447.2 W | 603.1 W | 773.0 W |
| Efficiency (2) | 82.3% | 86.1% | 86.4% | 85.6% | 84.5% |
| AC Voltage | 113.4 V | 112.0 V | 109.7 V | 108.1 V | 105.8 V |
| Power Factor | 0.996 | 0.996 | 0.997 | 0.998 | 0.998 |
Final Result | Pass | Pass | Pass | Pass | Pass |
Updated 06/25/2009: We re-tested this power supply using our new GWInsteak GPM-8212 power meter, which is a precision instrument and provides accuracy of 0.2% and thus presenting the correct readings for AC power and efficiency (results marked as "2" on the table above; results marked as "1" were measured with our previous power meter from Brand Electronics, which isn't so precise as you can see). We also added the numbers for AC voltage during our tests, an important number as efficiency is directly proportional to AC voltage (the higher AC voltage is, the higher efficiency is). Also, manufacturers usually announce efficiency at 230 V, which usually inflates efficiency numbers. We added power factor (PF) numbers as well. These numbers measure the efficiency of the power supply active PFC circuit. This number should be as close to 1 as possible. The active PFC circuit from this power supply is outstanding, as power factor was always above 0.996.
Efficiency is one of the highlights of this product. If you pull between 40% and 80% from this power supply maximum labeled wattage (between 260 W and 520 W) you will see an efficiency of at least 85.6%. At full load - traditionally the Achilles' Heel for efficiency - efficiency was of 84.5%, which is outstanding. Only at light load (20% load, i.e. 130 W) efficiency was relatively low, at 82.3%.
Voltage stability was great with all voltages within 3% from their nominal value, including the -12 V output, which is usually outside the 3% range.
Ripple and noise is another highlight from this product. When pulling its full labeled power – which is when power supplies usually show their worst noise levels – the +12V outputs were still at only 1/5 of the maximum admissible noise level and the +5 V and +3.3 V outputs were still below half of the maximum allowed. Ripple on -12 V output was also very low, at 33 mV when we were pulling 100% load.
Below you can see noise level when we were pulling 653 W (test number five) from this power supply. Just to remember, the maximum allowed for the +12 V outputs is 120 mV peak-to-peak and the maximum allowed for the +5 V and +3.3 V outputs is 50 mV peak-to-peak.

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Figure 17: Noise level at +12V1 input from our load tester with the reviewed unit delivering 653 W (22.6 mV).

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Figure 18: Noise level at +12V2 input from our load tester with the reviewed unit delivering 653 W (23 mV).

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Figure 19: Noise level at +5 V input from our load tester with the reviewed unit delivering 653 W (24 mV).

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Figure 20: Noise level at +3.3 V input from our load tester with the reviewed unit delivering 653 W (19.4 mV).
Let’s now see if we could pull even more power from Antec Signature 650.