PowerColor Extreme 850 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 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., th
e +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 input was connected to the power supply +12V2 and +12V3 rails, while the +12VB input was connected to the power supply +12V1 rail.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 6 A (72 W) | 13 A (156 W) | 18.5 A (222 W) | 25 A (300 W) | 31 A (372 W) |
| +12VB | 6 A (72 W) | 12 A (144 W) | 18.5 A (222 W) | 25 A (300 W) | 31 A (372 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 | 175.7 W | 354.8 W | 519.8 W | 696.4 W | 854.2 W |
| % Max Load | 20.7% | 41.7% | 61.2% | 81.9% | 100.5% |
| Room Temp. | 46.0° C | 46.2° C | 47.6° C | 45.0° C | 47.5° C |
| PSU Temp. | 48.1° C | 48.6° C | 49.5° C | 50.7° C | 53.3° C |
| Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 214.1 W | 417.5 W | 617.0 W | 842.0 W | 1072.0 W |
| Efficiency | 82.1% | 85.0% | 84.2% | 82.7% | 79.7% |
| AC Voltage | 113.1 V | 111.0 V | 109.3 V | 106.2 V | 102.9 V |
| Power Factor | 0.981 | 0.989 | 0.991 | 0.993 | 0.985 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
The PowerColor Extreme 850 W can really deliver its labeled wattage at high temperatures.
Efficiency was very decent when we pulled up to 80% of the unit’s labeled wattage (i.e., up to 680 W), between 82% and 85%. At full load, however, efficiency dropped below the 80% mark. This unit has the 80 Plus Bronze certification, however during the 80 Plus certification power supplies are tested at only 23° C, while we tested this particular unit at 47.5° C, and efficiency drops with temperature. We’ve seen this kind of problem happening over and over again.
Voltage regulation was very good, with all voltages within 3% of their nominal values, except +5 V during tests one and two (still inside the proper range, though). The ATX12V specification allows voltages to be up to 5% from their nominal values (10% for the -12 V output). Therefore this power supply presents voltages closer to their nominal values than necessary most of the time.
Noise and ripple levels, although below the maximum allowed, were high during test five, almost touching the limit. 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 18: +12VA input from load tester during test five at 854.2 W (101.2 mV)
Figure 19: +12VB input from load tester during test five at 854.2 W (96.6 mV)
Figure 20: +5V rail during test five at 854.2 W (37.2 mV)
Figure 21: +3.3 V rail during test five at 854.2 W (37.2 mV)
Let’s see if we can pull even more from the PowerColor Extreme 850 W.