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.
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 and +12V2 rails and the +12V2 input was connected to the power supply +12V1 rail (ATX12V connector).
Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
+12V1 | 2 A (24 W) | 4 A (48 W) | 6 A (72 W) | 8 A (96 W) | 10.5 A (126 W) |
+12V2 | 1.5 A (18 W) | 3.5 A (42 W) | 6 A (72 W) | 8 A (96 W) | 10 A (120 W) |
+5V | 1 A (5 W) | 2 A (10 W) | 3 A (15 W) | 4 A (20 W) | 5 A (25 W) |
+3.3 V | 1 A (3.3 W) | 2 A (6.6 W) | 3 A (9.9 W) | 4 A (13.2 W) | 5 A (16.5 W) |
+5VSB | 1 A (5 W) | 1 A (5 W) | 1.5 A (7.5 W) | 2 A (10 W0 | 2 A (10 W0 |
-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 | 60.4 W | 115.9 W | 179.2 W | 236.3 W | 296.0 W |
% Max Load | 20.1% | 38.6% | 59.7% | 78.8% | 98.7% |
Room Temp. | 39.0º C | 38.2º C | 38.6º C | 39.3º C | 39.8º C |
PSU Temp. | 42.8º C | 44.2º C | 43.5º C | 39.7º C | 46.0º C |
Voltage Stability | Pass | Pass | Pass | Pass | Fail on +5VSB |
Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
AC Power | 74.4 W | 138.0 W | 212.3 W | 283.7 W | 363.5 W |
Efficiency | 81.2% | 84.0% | 84.4% | 83.3% | 81.4% |
AC Voltage | 115.7 V | 115.1 V | 114.2 V | 113.4 V | 112.9 V |
Power Factor | 0.993 | 0.986 | 0.987 | 0.988 | 0.989 |
Final Result | Pass | Pass | Pass | Pass | Pass |
We had to be more generous with temperature while reviewing this power supply. We usually wait until the temperature inside our thermal chamber is between 45º C and 50º C to start collecting data, however since this is a low wattage unit, temperature delayed a lot to increase and the maximum we could get was 39º C.
FSP300-60GHS presents a very good efficiency around 83%-84% when you pull between 40% and 80% from its labeled capacity (i.e., between 120 W and 240 W). At light load (20% load, i.e., 60 W) and full load (300 W) efficiency dropped, but was still above 81%, what is good.
The main outputs (+12 V, +5 V and +3.3 V) were always 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. The standby voltage (+5VSB), however, touched the 4.75 V limit during test number four and dropped below it (4.72 V) during test number five.
Ripple and noise were 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.
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Figure 16: +12V1 input from load tester at 296.0 W (59 mV).
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Figure 17: +12V2 input from load tester at 296.0 W (65.2 mV).
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Figure 18: +5V rail with power supply delivering 296.0 W (29.8 mV).
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Figure 19: +3.3 V rail with power supply delivering 296.0 W (17.8 mV).
Let’s see if we could pull more than 300 W from this unit.
