Arctic Cooling Fusion 550RF Power Supply Review
Load Tests
Contents
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 behav
ed under each load. In the table below we list the load patterns we used and the results for each load.
But since we knew beforehand that we were dealing with a 500 W power supply – and not a 550 W as one would assume from its label –, we considered 500 W for its maximum capacity and the tests present on this page reflect this.
For the 100% load test we used two patterns. The first one, test number five, we respected the limits printed on the power supply label (17 A maximum for each +12 V rail). To achieve this pattern, however, we had to configure the +12 V outputs with a current lower than we wanted, and increase current on +5 V and +3.3 V outputs to a value higher than we wanted. After testing the power supply with this pattern, we configured our load tester with the pattern described below as test six, increasing current on +12 V outputs and lowering current on +5 V and +3.3 V outputs, which is the standard we use on our tests.
+12V1 and +12V2 are the two inputs from our load tester, with +12V1 input connected to the power supply +12V1 and +12V2 rails and with +12V2 input connected to the power supply +12V2 rail.
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 | Test 6 |
| +12V1 | 4 A (48 W) | 7 A (84 W) | 11 A (132 W) | 14.5 A (174 W) | 17 A (204 W) | 18 A (216 W) |
| +12V2 | 3 A (36 W) | 7 A (84 W) | 10 A (120 W) | 14 A (168 W) | 17 A (204 W) | 18 A (216 W) |
| +5V | 1 A (5 W) | 2 A (10 W) | 4 A (20 W) | 5 A (25 W) | 9 A (45 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) | 9 A (29.7 W) | 6 A (19.8 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) | 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) | 0.5 A (6 W) |
| Total | 101.8 W | 192.1 W | 292.8 W | 388.9 W | 488.6 W | 482.4 W |
| % Max Load | 20.4% | 38.4% | 58.6% | 77.8% | 97.7% | 96.5% |
| Room Temp. | 46.3° C | 45.9° C | 47.1° C | 47.3° C | 50.0° C | 50.0° C |
| PSU Temp. | 47.5° C | 47.4° C | 47.6° C | 47.8° C | 50.4° C | 48.7° C |
| Voltage Stability | Fail | Fail | Fail | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass | Pass |
| AC Power | 114 W | 214 W | 331 W | 453 W | 587 W | 578 W |
| Efficiency | 89.3% | 89.8% | 88.5% | 85.8% | 83.2% | 83.5% |
| Final Result | Fail | Fail | Fail | Pass | Pass | Pass |
Arctic Cooling 550RF achieved an excellent efficiency between 85.8% and 89.8% when we pulled up to 80% of its real wattage (500 W), i.e., up to 400 W. When we pulled 500 W efficiency dropped, but to 83%, which is still a very good result.
The problem, however, was that during tests one, two and three +12V voltages where at 10.8 V and thus below the minimum allowed (11.4 V). This is not good.
Noise and ripple on the other hand were at very good levels. During test number five we saw 45 mV at +12V1, 49 mV at +12V2, 20 mV at +5 V and 10.2 mV at +3.3 V. The maximum allowed values are 120 mV for the +12 V outputs and 50 mV for the +5 V and +3.3 V outputs and we always want to see noise at half of the maximum allowed or below that, feat accomplished by this unit. All values are peak-to-peak.
Figure 15: Noise level at +12V1 during test six (43.6 mV).
Figure 16: Noise level at +12V2 during test six (49.8 mV).
Figure 17: Noise level at +5 V during test six (16.4 mV).
Figure 18: Noise level at +3.3 V during test six (10 mV).
Now let’s see if we can pull even more power from Fusion 550RF.