Seventeam ST-650PWL 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 the behavior of the reviewed unit 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 powers listed for each test, you may find a different value than what is posted under “Total” below. Since each output can have a slight variation (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. In 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 our tests, the +12VA and +12VB input were connected to the power supply single +12 V rail (the EPS12V connector was installed on the +12VB input of our load tester).
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 5 A (60 W) | 10 A (120 W) | 15 A (180 W) | 20 A (240 W) | 23.75 A (285 W) |
| +12VB | 5 A (60 W) | 10 A (120 W) | 15 A (180 W) | 20 A (240 W) | 23.75 A (285 W) |
| +5V | 1 A (5 W) | 2 A (10 W) | 4 A (20 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) | 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) |
| -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 | 142.0 W | 271.8 W | 400.2 W | 548.6 W | 655.8 W |
| % Max Load | 21.8% | 41.8% | 61.6% | 84.4% | 100.9% |
| Room Temp. | 46.8° C | 45.9° C | 47.2° C | 45.2° C | 48.8° C |
| PSU Temp. | 46.6° C | 48.0° C | 48.7° C | 47.6° C | 50.5° C |
| Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 172.6 W | 320.5 W | 473.6 W | 664.0 W | 812.0 W |
| Efficiency | 82.3% | 84.8% | 84.5% | 82.6% | 80.8% |
| AC Voltage | 115.2 V | 113.3 V | 111.5 V | 109.2 V | 107.5 V |
| Power Factor | 0.971 | 0.984 | 0.991 | 0.994 | 0.996 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
The Seventeam ST-650PWL can really deliver its labeled wattage at high temperatures.
Efficiency was good, between 80.8% and 84.5%. This unit has the 80 Plus Bronze certification, meaning that it should be able to present at least 82% efficiency at light (20%) and full loads, and at least 85% efficiency at typical (50%) load. During our tests, however, this unit had 80.8% efficiency at full load. We see this happening all the time, since Ecos Consulting (the company behind the 80 Plus certification) tests power supplies at only 23° C, and we tested this particular unit between 45° C and 49° C, and efficiency drops with temperature.
Voltages were always inside their proper range (5% for the positive voltages and 10% for the -12 V output). During our tests the +12 V, +3.3 V and +5VSB outputs were closer to their nominal values than necessary (3% regulation), but we didn’t see the same happening with the +5 V and -12 V outputs, but they were still inside the allowed range.
Noise and ripple levels were low, except the +3.3 V and +5VSB outputs during test five. The 3.3 V presented a high level of noise and ripple, but they were still below the maximum allowed. The noise and ripple levels at +5VSB output, however, was exactly at 50 mV, which is the maximum allowed. Below you can see the results for the power supply outputs during test number five. The maximum allowed is 120 mV for the +12 V and -12 V outputs, and 50 mV for the +5 V, +3.3 V, and +5VSB outputs. All values are peak-to-peak figures.
Figure 16: +12VA input from load tester during test five at 655.8 W (30.4 mV)
Figure 17: +12VB input from load tester during test five at 655.8 W (31.2 mV)
Figure 18: +5V rail during test five at 655.8 W (31.2 mV)
Figure 19: +3.3 V rail during test five at 655.8 W (42.2 mV)
Let’s see if we can pull even more from the Seventeam ST-650PWL.