Test Setup
Primary Rails Load Regulation
The following charts show the voltage values of the main rails, recorded over a range from 60 W to the maximum specified load, and the deviation (in percent) for the same load range. Tight load regulation is essential for every power supply because it allows for constant voltage levels despite changes in load.
5VSB Regulation
Load regulation is within 1% at +12 V, which is pretty good. However, it is loose on the other rails.
Ripple Measurements
Ripple represents the AC fluctuations (periodic) and noise (random) found in the DC rails of PSUs. Ripple significantly decreases the life span of capacitors because it increases their temperature; a 10 °C increase can cut into a capacitor's life span by up to 50 percent. Ripple also plays a vital role in overall system stability, especially when it is overclocked. According to the ATX specification, the ripple limits are 120 mV (+12V) and 50 mV (+5V, +3.3V, and 5VSB).
Ripple Measurements - 1st Player SFX 7.5 750W |
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Test | 12V | 5V | 3.3V | 5VSB | Pass/Fail |
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10% Load | 6.9 mV | 10.3 mV | 6.1 mV | 10.1 mV | Pass |
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20% Load | 14.1 mV | 10.7 mV | 7.2 mV | 10.3 mV | Pass |
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30% Load | 12.1 mV | 11.8 mV | 8.0 mV | 10.4 mV | Pass |
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40% Load | 11.6 mV | 12.2 mV | 8.7 mV | 11.0 mV | Pass |
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50% Load | 13.4 mV | 12.9 mV | 9.6 mV | 12.5 mV | Pass |
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60% Load | 13.6 mV | 14.1 mV | 10.5 mV | 12.7 mV | Pass |
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70% Load | 14.6 mV | 14.7 mV | 12.1 mV | 13.1 mV | Pass |
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80% Load | 15.6 mV | 15.2 mV | 12.5 mV | 14.2 mV | Pass |
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90% Load | 17.3 mV | 16.9 mV | 13.8 mV | 14.7 mV | Pass |
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100% Load | 26.9 mV | 18.8 mV | 15.7 mV | 17.4 mV | Pass |
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Crossload 1 | 21.1 mV | 16.9 mV | 10.3 mV | 10.9 mV | Pass |
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Crossload 2 | 15.1 mV | 17.6 mV | 6.8 mV | 11.4 mV | Pass |
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Crossload 3 | 6.8 mV | 12.9 mV | 9.9 mV | 9.8 mV | Pass |
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Crossload 4 | 26.0 mV | 15.5 mV | 13.7 mV | 16.4 mV | Pass |
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Ripple suppression is quite good for the standards of the SFX form factor.
Ripple at Full Load
Ripple at Crossload 1
Ripple at Crossload 4