We conducted 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 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.
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.
The +12V1 and +12V2 inputs listed below are the two +12 V independent inputs from our load tester. During this test both were connected to the single +12 V rail from this power supply.
Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
+12V1 | 7 A (84 W) | 14 A (168 W) | 21 A (252 W) | 28 A (336 W) | 32 A (384 W) |
+12V2 | 7 A (84 W) | 14 A (168 W) | 21 A (252 W) | 28 A (336 W) | 32 A (384 W) |
+5V | 2 A (10 W) | 4 A (20 W) | 6 A (30 W) | 8 A (40 W) | 19 A (95 W) |
+3.3 V | 2 A (6.6 W) | 4 A (13.2 W) | 6 A (19.8 W) | 8 A (26.4 W) | 19 A (62.7 W) |
+5VSB | 1 A (5 W) | 2 A (10 W) | 2 A (10 W) | 3 A (15 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 | 197.7 W | 388.8 W | 579.1 W | 762.8 W | 945.8 W |
% Max Load | 20.8% | 40.9% | 61.0% | 80.3% | 99.6% |
Room Temp. | 45.5º C | 46.5º C | 48.2º C | 48.2º C | 48.6º C |
PSU Temp. | 48.4º C | 51.1º C | 52.0º C | 53.8º C | 55.3º C |
Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
AC Power | 225.4 W | 437.4 W | 652.0 W | 885.0 W | 1145.0 W |
Efficiency | 87.7% | 88.9% | 88.8% | 86.2% | 82.6% |
AC Voltage | 113.7 V | 112.2 V | 110.3 V | 107.0 V | 102.6 V |
Power Factor | 0.983 | 0.993 | 0.996 | 0.997 | 0.998 |
Final Result | Pass | Pass | Pass | Pass | Pass |
Corsair TX950W can really deliver 950 W at almost 50º C.
Efficiency was very high in all load patterns (between 86% and 88.9%, as you can see on the table above) except during test five, where it dropped to 82.6%. Keeping high efficiency at a high load like 950 W is not an easy task.
There is one important detail to keep in mind. For the test five we were limited by our load tester and we could not pull more current from its +12 V inputs as we’d like to (we had to pull more current from +3.3 V and +5 V than we usually do in order to achieve 950 W), and this different pattern may have contributed to this lower efficiency.
This unit is 80 Plus Silver certified, but Corsair decided to label it as an 80 Plus Bronze model because of the ridiculously low temperature Ecos Consulting, the company behind the 80 Plus certification, tests power supplies (23º C, which is impossible to be achieved inside a PC, especially a high-end one that will get a 950 W power supply). Since we test power supplies at a temperature between 45º C and 50º C, this explains why in our reviews efficiency is always lower than the one found on 80 Plus reports (the higher the temperature, the lower efficiency is).
As you can see, in our tests Corsair TX750W would fail on our own way to test for the 80 Plus Silver certification (85% minimum efficiency at full load) but it passes the 80 Plus Bronze certification (82% minimum efficiency at full load). As you can clearly see, Corsair agrees with us and this is not the first time we’ve seen Corsair downgrading an 80 Plus certification because they don’t feel comfortable with the results. In a world full of companies trying to illude consumers, it is amazing to find a company doing the opposite. Kudos to Corsair.
Voltage regulation was very good, with all voltages inside 3% of their nominal values during testes one through four(i.e., voltages were closer to their nominal value than needed, as ATX spec allows voltages to be up to 5% from their nominal values, 10% for -12 V). This includes the -12 V output, which usually doesn’t like to stay within a tolerance this tight. During test five +5 V and +3.3 V outputs were outside this tighter range but still inside the allowed margin (5%), probably due to the different load pattern we had to use, as explained.
And finally we have noise and ripple, which were low all the time. Below you can see the results for test number five. As we always point out, the limits are 120 mV for +12 V and 50 mV for +5 V and +3.3 V and all numbers are peak-to-peak figures.
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Figure 18: +12V1 input from load tester at 945.8 W (60.6 mV).
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Figure 19: +12V2 input from load tester at 945.8 W (55.6 mV).
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Figure 20: +5V rail with power supply delivering 945.8 W (11.8 mV).
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Figure 21: +3.3 V rail with power supply delivering 945.8 W (14.6 mV).
Now let’s see if we could pull more than 950 W from this unit.
