We conducted several tests with this power supply, as described in the article Hardware Secrets Power Supply Test Methodology. All the tests described below were taken with a room temperature between 45.5º and 50º C. During our tests the power supply temperature was between 50º and 56º C.
First we tested this power supply with five different load patterns, trying to pull around 20%, 40%, 60%, 80%, and 100% of its labeled maximum capacity (actual percentage used listed under “% Max Load”), watching how the reviewed unit behaved under each load. In the table below we list the load patterns we used and the results for each load.
+12V2 is the second +12V input of our load tester and on this test it was connected to the power supply EPS12V connector.
If you add all the power listed for each test, you may find a different value than what is posted under “Total” below. Since each output can vary slightly (e.g., the +5 V output working at 5.10 V), the actual total amount of power being delivered is slightly different than the calculated value. On the “Total” row we are using the real amount of power being delivered, as measured by our load tester.
Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
+12V1 | 5 A (60 W) | 10 A (120 W) | 14 A (168 W) | 18.5 A (222 W) | 25.5 A (306 W) |
+12V2 | 4 A (48 W) | 8.5 A (102 W) | 13 A (156 W) | 18 A (216 W) | 20 A (240 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 A (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) | 0.8 A (9.6 W) |
Total | 128 W | 250 W | 374 W | 498 W | 618 W |
% Max Load | 20.6% | 40.3% | 60.3% | 80.3% | 99.7% |
Result | Pass | Pass | Pass | Pass | Pass |
Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
AC Power | 149 W | 284 W | 432 W | 585 W | 745 W |
Efficiency | 85.9% | 88.0% | 86.6% | 85.1% | 82.9% |
Corsair HX620W proved to be an outstanding power supply. As you can see, it could deliver its rated power with a room temperature of 50º C, which is impressive. This power supply also provides one of the best efficiencies on the market. At full load it presented an 83% efficiency and at 40% load (250 W) it presented an amazing 88% efficiency.
Voltage stability was also one of the highlights during our tests. All outputs were within 3% of the nominal voltage during all tests, which is outstanding, as ATX spec states that regulation should be within 5%. Translation: the voltages were closer to their nominal values than what is stated by the ATX standard.
Electrical noise was also at a very low level (always below 40 mV on +12 V, below 8 mV on +5 V and below 7 mV on +3.3 V – ATX spec states a maximum noise level of 120 mV for +12 V and 50 mV for both +5 V and +3.3 V outputs), and we really impressed by that, because the Corsair TX750W power supply we reviewed recently had a very high noise level. The reason of the difference is probably due to the different manufacturer of the power supply – HX620W is manufactured by Seasonic, while TX750W is manufactured by CWT.
Just to put things into perspective, the noise level achieved by Corsair HX620W was lower than PC Power and Cooling Silencer 610 EPS12V, a product that has a very low noise level. This is simply fantastic.
Below we show the noise level we found on the power supply outputs while the unit was operating at its full load (test number five): +12V1 input was at 38.6 mV, +12V2 input was at 34.4 mV, +5 V input was at 7.8 mV and +3.3 V input was at 6.8 mV. Great numbers.
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Figure 22: Noise level at +12V1 input of the load tester.
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Figure 23: Noise level at +12V2 input of the load tester.
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Figure 24: Noise level at +5V input of the load tester.
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Figure 25: Noise level at +3.3V input of the load tester.
