Rocketfish 550 W 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.
For our tests we assumed this power supply a being a 500 W model. Then we added a sixth load pattern with a 550 W load, to see if this unit could really deliver 550 W or not.
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 rail and the +12V2 input was connected to the power supply +12V2 rail.
| 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) | 18 A (216 W) | 20 A (240 W) |
| +12V2 | 3 A (36 W) | 7 A (84 W) | 10 A (120 W) | 14 A (168 W) | 18 A (216 W) | 19 A (228 W) |
| +5V | 1 A (5 W) | 2 A (10 W) | 4 A (20 W) | 5 A (25 W) | 6 A (30 W) | 8 A (40 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) | 8 A (26.4 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 | 104.2 W | 196.0 W | 298.6 W | 396.2 W | 492.3 W | 545.1 W |
| % Max Load | 20.8% | 39.2% | 59.7% | 79.2% | 98.5% | 109.0% |
| Room Temp. | 45.8° C | 46.5° C | 45.9° C | 48.3° C | 46.2° C | 46.5° C |
| PSU Temp. | 44.9° C | 45.9° C | 44.2° C | 47.1° C | 47.3° C | 47.1° C |
| Voltage Stability | Pass | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass | Pass |
| AC Power | 122.2 W | 229.3 W | 351.6 W | 476.5 W | 609.0 W | 681.0 W |
| Efficiency | 85.3% | 85.5% | 84.9% | 83.1% | 80.8% | 80.0% |
| AC Voltage | 112.5 V | 110.1 V | 110.6 V | 107.9 V | 106.2 V | 106.4 V |
| Power Factor | 0.979 | 0.993 | 0.996 | 0.997 | 0.998 | 0.998 |
| Final Result | Pass | Pass | Pass | Pass | Pass | Fail |
When we tried to pull more than 500 W the power supply would shut down after a few seconds, showing that it is really a 500 W product. On the good side, it protections entered in action and we didn’t burn or explode this unit while trying to pull more than it is capable of delivering.
So for all practical effects we must consider this a 500 W unit.
Rocketfish 550 W presents an outstanding efficiency of 85% if you pull up to 300 W from it – which is what most people buying this unit will be pulling anyway. Pulling around 400 W efficiency was still pretty decent at 83%. At 500 W, however, efficiency dropped to 80.8%, still above the 80% mark.
Voltage stability is another highlight from this product. All voltages were within 3% from their nominal value, whereas the ATX specification says they must be within 5%. Translation: voltages were closer to their nominal values than needed. This includes the -12 V output, which usually likes to stay outside this range.
Ripple and noise were very low. With this power supply delivering 500 W noise level at +12 V outputs were less than half the maximum allowed. Noise on +3.3 V was very low while noise on +5 V was super low. You can see the results for test number five below. All numbers are peak-to-peak figures and the maximum allowed is 120 mV for the +12 V outputs and 50 mV for the +3.3 V and +5 V outputs.
Figure 16: +12V1 input from load tester at 492.3 W (49.4 mV).
Figure 17: +12V2 input from load tester at 492.3 W (51.4 mV).
Figure 18: +5V rail with power supply delivering 492.3 W (11.2 mV).
Figure 19: +3.3 V rail with power supply delivering 492.3 W (16.4 mV).
Over current protection was present and active. The power supply wouldn’t turn on if we tried to pull more than 26 A from any one of its two rails.