We conducted several tests with this power supply, as described in the article Hardware Secrets Power Supply Test Methodology.
As you are probably already familiar, we test power supplies with five different load patterns, trying to pull around 20%, 40%, 60%, 80%, and 100% of its labeled maximum capacity. However, since we were suspecting that this would be a 450 W unit, we added a load pattern for this power range (which is equivalent of around 90% of 500 W), respecting the 360 W limit for the +12 V outputs that was posted on the label (test number five).
Then for the 100% load test we used two patterns, one respecting this 360 W limit (test number six), which made us to pull more power from +5 V and +3.3 V than we wanted to, and another not respecting it (test number seven), pulling more power from +12 V, since this is the way we usually test power supplies, as nowadays most power is concentrated on the +12 V rails as the CPU and the video card are connected to them.
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.
+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) while the +12V2 input was connected to the power supply +12V2 rail (EPS12V connector).
Input | Test 1 | Test 2 | Test 3 | Test 4 |
+12V1 | 4 A (48 W) | 7 A (84 W) | 11 A (132 W) | 14.5 A (174 W) |
+12V2 | 3 A (36 W) | 7 A (84 W) | 10 A (120 W) | 14 A (168 W) |
+5V | 1 A (5 W) | 2 A (10 W) | 4 A (20 W) | 5 A (25 W) |
+3.3 V | 1 A (3.3 W) | 2 A (6.6 W) | 4 A (13.2 W) | 5 A (16.5 W) |
+5VSB | 1 A (5 W) | 1 A (5 W) | 1.5 A (7.5 W) | 2 A (10 W) |
-12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
Total | 102.9 W | 194.3 W | 295.0 W | 392.0 W |
% Max Load | 20.6% | 38.9% | 59.0% | 78.4% |
Room Temp. | 48.4º C | 48.3º C | 47.1º C | 48.8º C |
PSU Temp. | 50.2º C | 50.1º C | 48.9º C | 52.3º C |
Voltage Stability | Pass | Pass | Pass | Pass |
Ripple and Noise | Pass | Pass | Pass | Fail |
AC Power | 132 W | 239 W | 366 W | 503 W |
Efficiency | 78.0% | 81.3% | 80.6% | 77.9% |
Final Result | Pass | Pass | Pass | Fail |
Input | Test 5 | Test 6 | Test 7 |
+12V1 | 15 A (180 W) | 15 A (180 W) | 18 A (216 W) |
+12V2 | 15 A (180 W) | 15 A (180 W) | 18 A (216 W) |
+5V | 9 A (45 W) | 15 A (75 W) | 6 A (30 W) |
+3.3 V | 9 A (29.7 W) | 15 A (49.5 W) | 6 A (19.8 W) |
+5VSB | 2.5 A (12.5 W) | 2.5 A (12.5 W) | 2.5 A (12.5 W) |
-12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
Total | 446.9 W | 499.9 W | 485.5 W |
% Max Load | 89.4% | 100.0% | 97.1% |
Room Temp. | 46.8º C | 47.4º C | 50.9º C |
PSU Temp. | 54.1º C | 50.6º C | 55.1º C |
Voltage Stability | Pass | Pass | Pass |
Ripple and Noise | Fail | Fail | Fail |
AC Power | 588 W | 681 W | 659 W |
Efficiency | 76.0% | 73.4% | 73.7% |
Final Result | Fail | Fail | Fail |
Cooler Master eXtreme 500 W could deliver 500 W, however power isn’t everything. Efficiency was above 80% only when we pulled between 40% and 60% (200 W – 300 W) from the power supply nominal maximum power, and when we pulled its full power efficiency was at the 73% range, which is really bad.
But the real problem with this power supply is its ripple and noise level. When we pulled 60% of the power supply maximum power noise level at +12V1 and +12V2 was at 104.4 mV and 98.9 mV, respectively. Very high, but still within the 120 mV set by ATX specs. But from 80% load on ripple and noise level was always above specs: 128.6 mV and 122.2 mV during test number four, 130.2 mV and 125.6 mV during test number five, 172.6 mV and 167.4 mV during test number six and 149.6 mV and 145.4 mV during test number seven. These numbers are for +12V1 and +12V2 rails, respectively, and are peak-to-peak figures.
Noise level at +3.3 V was always below 20.4 mV, which is good, but +5 V output reached 49.2 mV during test number six, hitting the 50 mV limit for this output.
Below you see the images for ripple and noise during test number seven.
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Figure 14: Noise level at +12V1 input from our load tester with the reviewed unit delivering 485.5 W (149.6 mV).
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Figure 15: Noise level at +12V2 input from our load tester with the reviewed unit delivering 485.5 W (145.4 mV).
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Figure 16: Noise level at +5 V input from our load tester with the reviewed unit delivering 485.5 W (42.4 mV).
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Figure 17: Noise level at +3.3 V input from our load tester with the reviewed unit delivering 485.5 W (20.4 mV).
