Cougar GX 700 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 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 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. 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 this test the +12VA input was connected to the power supply +12V1 and +12V4 rails, while the +12VB input was connected to the power supply +12V2 and +12V3 rails (EPS12V connector).
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 4.5 A (54 W) | 9.5 A (114 W) | 14.5 A (174 W) | 19 A (228 W) | 25 A (300 W) |
| +12VB | 4.5 A (54 W) | 9.5 A (114 W) | 14.5 A (174 W) | 19 A (228 W) | 25 A (300 W) |
| +5V | 2 A (10 W) | 4 A (20 W) | 6 A (30 W) | 8 A (40 W) | 10 A (50 W) |
| +3.3 V | 2 A (6.6 W) | 4 A (13.2 W) | 6 A (19.8 W) | 8 A (26.4 W) | 10 A (33 W) |
| +5VSB | 1 A (5 W) | 1.5 A (7.5 W) | 2 A (10 W) | 2.5 A (12.5 W) | 3 A (15 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 | 137.3 W | 276.5 W | 413.4 W | 537.3 W | 698.8 W |
| % Max Load | 19.6% | 39.5% | 59.1% | 76.8% | 99.8% |
| Room Temp. | 45.2° C | 46.0° C | 47.0° C | 48.3° C | 45.4° C |
| PSU Temp. | 42.2° C | 44.2° C | 45.7° C | 46.7° C | 47.3° C |
| Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 159.6 W | 312.3 W | 469.6 W | 616.0 W | 813.0 W |
| Efficiency | 86.0% | 88.5% | 88.0% | 87.2% | 86.0% |
| AC Voltage | 113.1 V | 111.5 V | 110.1 V | 109.0 V | 106.3 V |
| Power Factor | 0.986 | 0.991 | 0.996 | 0.997 | 0.998 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
The Cougar GX 700 W can really deliver its labeled wattage at high temperatures.
Efficiency was always very high, between 86% and 88.5%. Nice numbers, but there is just one small detail: this unit has the 80 Plus Gold certification and should be able to deliver 87% efficiency at light (20%) and full loads, and 90% efficiency at typical (50%) load. We see this kind of problem happening all the time. Unfortunately, Ecos Consulting, the company behind the 80 Plus certification, tests power supplies at 23° C, which is an unrealistic temperature. We test power supplies between 45° C and 50° C, which is a more realistic scenario, and since efficiency drops with temperature, we usually get lower efficiency numbers than those published by the 80 Plus certification. Because of this issue, we consider our numbers more realistic than those provided by manufacturers and by the 80 Plus certification.
Voltages were inside a tighter 3% tolerance during tests one, two, and three. The +5 V output got out of this tighter tolerance during the tests four and five, and the +3.3 V output got out of this tighter range during test five. They were, however, still inside the proper range.
Noise and ripple levels were always very low. Below you can see the results for the power supply outputs during test number five. The maximums allowed are 120 mV for +12 V and -12 V and 50 mV for +5 V and +3.3 V. All values are peak-to-peak figures.
Figure 18: +12VA input from load tester during test five at 698.8 W (38.2 mV)
Figure 19: +12VB input from load tester during test five at 698.8 W (35.6 mV)
Figure 20: +5V rail during test five at 698.8 W (27.6 mV)
Figure 21: +3.3 V rail during test five at 698.8 W (25.6 mV)
Let’s see if we can pull even more from the Cougar GX 700 W.