Gigabyte Superb 550P 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 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” be
low. 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 +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During this test the +12VA input was connected to the power supply +12V1 rail, while the +12VB input was connected to the power supply +12V2 rail.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 3 A (36 W) | 6.5 A (78 W) | 9.5 A (114 W) | 13 A (156 W) | 17 A (204 W) |
| +12VB | 3 A (36 W) | 6.5 A (78 W) | 9.5 A (114 W) | 13 A (156 W) | 16.5 A (198 W) |
| +5V | 1 A (5 W) | 2 A (10 W) | 4 A (20 W) | 5 A (25 W) | 7 A (35 W) |
| +3.3 V | 1 A (5 W) | 2 A (6.6 W) | 4 A (13.2 W) | 5 A (16.5 W) | 7 A (23.1 W) |
| +5VSB | 1 A (5 W) | 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) | 0.5 A (6 W) |
| Total | 90.9 W | 181.9 W | 269.0 W | 357.4 W | 448.4 W |
| % Max Load | 20.2% | 40.4% | 59.8% | 79.4% | 99.6% |
| Room Temp. | 45.2° C | 44.8° C | 45.2° C | 47.0° C | 45.5° C |
| PSU Temp. | 48.8° C | 48.8° C | 49.6° C | 51.5° C | 52.5° C |
| Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 118.4 W | 227.6 W | 341.1 W | 469.0 W | 625.0 W |
| Efficiency | 76.8% | 79.9% | 78.9% | 76.2% | 71.7% |
| AC Voltage | 115.3 V | 114.3 V | 112.2 V | 110.9 V | 109.3 V |
| Power Factor | 0.625 | 0.673 | 0.682 | 0.688 | 0.693 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
We tested Gigabyte Superb 550P as being a 450 W unit; as such it could deliver its labeled wattage at high temperatures.
The main problem with this unit is its efficiency. Although peaking practically 80% when we pulled between 180 W and 270 W (between 40% and 60% from its labeled maximum wattage), it dropped to around 72% when we pulled 450 W from it.
Voltage regulation, on the other hand, was excellent, with all voltages within 3% of their nominal values – i.e., voltages closer to their “face value” than required (ATX12V specification allows 5% tolerance for positive voltages and 10% for negative voltages). The exception was during test five, when the +12 V outputs dropped below this tighter tolerance, but still within the allowed range.
Noise and ripple, although below the maximum allowed, were a little bit higher than we’d like to see during test five. Below you can see the results for test five. The maximum allowed is 120 mV on +12 V and 50 mV on +5 V and +3.3 V. All these numbers are peak-to-peak figures.
Figure 18: +12VA input from load tester at 448.4 W (81.2 mV).
Figure 19: +12VB input from load tester at 448.4 W (77.6 mV).
Figure 20: +5 V rail with power supply delivering 448.4 W (32.6 mV).
Figure 21: +3.3 V rail with power supply delivering 448.4 W (28.4 mV).
Let’s see if we can pull more than 450 W from this unit.