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Load Regulation, Hold-Up Time & Inrush Current

To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units.

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Primary Rails And 5VSB Load Regulation

Load Regulation testing is detailed here.

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Hold-Up Time

Our hold-up time tests are described in detail here.

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The hold-up time is a breath away from 17ms, so we're giving SilverStone a pass. The power-good signal drops before the rails go out of spec, though, according to the ATX spec, it should be at least 1ms away from the actual hold-up time.

Inrush Current

For details on our inrush current testing, please click here.

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The small NTC thermistor doesn't do a very good job at limiting inrush current; our measurement is way too high for a low-capacity PSU.

Load Regulation And Efficiency Measurements

Our first set of tests reveals the stability of the voltage rails and the ST45SF's efficiency. The applied load equals (approximately) 10 to 110 percent of the PSU's maximum load in increments of 10 percentage points.

We conducted two additional tests. During the first, we stressed the two minor rails (5V and 3.3V) with a high load, while the load at +12V was only 0.1A. This test reveals whether a PSU is compatible with Intel's C6/C7 sleep states or not. In the second test, we determined the maximum load the +12V rail could handle with minimal load on the minor rails.

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Test #	12V	5V	3.3V	5VSB	DC/AC (Watts)	Efficiency	Fan Speed	Fan Noise	Temps (In/Out)	PF/AC Volts
1	1.911A	1.966A	1.956A	0.971A	44.777	80.270%	1050 RPM	17.5 dB(A)	38.14°C	0.964
12.148V	5.076V	3.368V	5.144V	55.783	41.06°C	115.19V
2	4.853A	2.959A	2.945A	1.166A	89.742	85.431%	1050 RPM	17.5 dB(A)	38.42°C	0.981
12.133V	5.065V	3.359V	5.130V	105.046	41.55°C	115.19V
3	8.153A	3.464A	3.459A	1.365A	134.904	86.886%	1050 RPM	17.5 dB(A)	38.94°C	0.985
12.119V	5.058V	3.351V	5.117V	155.265	42.09°C	115.20V
4	11.450A	3.963A	3.944A	1.565A	179.761	86.936%	1250 RPM	19.0 dB(A)	39.65°C	0.988
12.103V	5.049V	3.344V	5.102V	206.775	43.06°C	115.20V
5	14.418A	4.969A	4.946A	1.766A	224.784	86.555%	1640 RPM	24.5 dB(A)	40.61°C	0.990
12.088V	5.036V	3.334V	5.088V	259.702	44.17°C	115.20V
6	17.393A	5.973A	5.954A	1.970A	269.756	86.010%	2050 RPM	29.8 dB(A)	41.51°C	0.991
12.072V	5.024V	3.323V	5.073V	313.633	45.17°C	115.20V
7	20.374A	6.987A	6.968A	2.170A	314.751	85.591%	2350 RPM	35.0 dB(A)	42.17°C	0.995
12.057V	5.013V	3.315V	5.059V	367.737	46.56°C	115.20V
8	23.365A	7.999A	7.985A	2.375A	359.696	84.762%	2675 RPM	37.5 dB(A)	43.04°C	0.995
12.040V	5.002V	3.305V	5.044V	424.360	47.64°C	115.19V
9	26.797A	8.516A	8.523A	2.380A	404.724	83.969%	2750 RPM	40.5 dB(A)	43.86°C	0.993
12.022V	4.990V	3.296V	5.035V	481.992	48.58°C	115.18V
10	29.978A	9.046A	9.030A	2.995A	449.577	82.823%	2765 RPM	41.1 dB(A)	44.96°C	0.991
12.004V	4.979V	3.288V	5.005V	542.814	49.82°C	115.18V
11	33.771A	9.061A	9.050A	3.000A	494.522	81.766%	2785 RPM	41.5 dB(A)	45.63°C	0.987
11.986V	4.972V	3.282V	4.996V	604.800	50.69°C	115.19V
CL1	0.098A	13.019A	13.003A	0.004A	109.720	79.906%	1680 RPM	25.3 dB(A)	42.86°C	0.983
12.112V	5.012V	3.327V	5.131V	137.311	47.03°C	115.20V
CL2	37.472A	1.004A	1.002A	1.002A	463.530	83.791%	2750 RPM	40.5 dB(A)	44.22°C	0.991
12.011V	5.022V	3.316V	5.079V	553.198	48.14°C	115.18V

Load regulation at +12V is quite tight, given this PSU's SFX form factor. At 5V and 3.3V, it remains within 3%. That's decent.

The small fan is quiet up to 1050 RPM. And even at full speed it's not as noisy as we expected. SilverStone's fan profile gets aggressive during the sixth test. An operating temperature over 41°C forces it to work hard, keeping the PSU's internals from overheating.

Finally, we observe low efficiency levels compared to PSUs with higher efficiency certifications. But don't forget that this is a budget-oriented power supply.

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