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 this test, the +12VA and +12VB inputs were connected to the power supply’s single +12 V rail. (The +12V2 input was connected to the power supply’s EPS12V connector.)
|Input||Test 1||Test 2||Test 3||Test 4||Test 5|
|+12VA||6 A (72 W)||13 A (156 W)||19 A (228 W)||25.5 A (306 W)||32 A (384 W)|
|+12VB||6 A (72 W)||13 A (156 W)||19 A (228 W)||25.5 A (306 W)||31.5 A (378 W)|
|+5 V||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)||1.5 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||166.5 W||348.3 W||512.8 W||688.4 W||852.8 W|
|% Max Load||19.6%||41.0%||60.3%||81.0%||100.3%|
|Room Temp.||45.6° C||45.3° C||45.8° C||48.3° C||49.4° C|
|PSU Temp.||44.2° C||44.8° C||45.8° C||47.6° C||50.5° C|
|Ripple and Noise||Pass||Pass||Pass||Pass||Pass|
|AC Power||197.2 W||401.4 W||595.2 W||814.0 W||1,042.0 W|
|AC Voltage||117.6 V||115.6 V||113.7 V||111.3 V||108.9 V|
The Kingwin Power Force 850 W was approved on our tests. The 80 Plus Bronze certification promises efficiency of at least 82% at light (20%) and full (100%) loads, and at least 85% at typical (50%) load. The reviewed power supply was able to match those numbers. (At full load, we saw 81.8% efficiency, which we can round up to 82%, especially because we test power supplies at high temperatures, and the tests for the 80 Plus Certification are conducted at low temperatures; efficiency drops as temperature increases.)
Voltage regulation was also outstanding, with all voltages within 3% of their nominal values, except for the -12 V output during test five, which was at -12.41 V, still inside the allowed range. The ATX12V specification states that positive voltages must be within 5% of their nominal values, and negative voltages must be within 10% of their nominal values.
Let’s discuss the ripple and noise levels on the next page.