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be quiet! SFX L Power 600W PSU Review

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. 

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 right where it should be. And although the power-good signal is a little shorter than the ATX spec's recommendation, it's still accurate, which is what matters most.

Inrush Current

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

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The lack of an NTC thermistor leads to very high inrush currents. High Power should make the necessary changes to this platform as soon as possible!

Load Regulation And Efficiency Measurements

The first set of tests reveals the stability of the voltage rails and the SFX L Power 600W'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.

Test #12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan SpeedFan NoiseTemps (In/Out)PF/AC Volts
13.117A1.974A1.954A0.996A59.78783.863%1400 RPM27.3 dB(A)38.14°C0.972
27.260A2.968A2.938A1.199A119.81388.488%1435 RPM28.6 dB(A)38.70°C0.992
311.752A3.478A3.446A1.400A179.88589.971%1455 RPM29.5 dB(A)38.95°C0.995
416.250A3.975A3.935A1.607A239.76190.528%1550 RPM30.2 dB(A)39.17°C0.997
520.419A4.980A4.932A1.816A299.77590.480%1560 RPM30.4 dB(A)39.79°C0.998
624.585A5.987A5.931A2.020A359.73590.148%1610 RPM31.3 dB(A)40.24°C0.998
728.755A7.009A6.939A2.231A419.74189.657%1655 RPM32.2 dB(A)41.27°C0.999
832.928A8.023A7.956A2.445A479.67489.069%1765 RPM34.2 dB(A)42.46°C0.999
937.532A8.534A8.484A2.445A539.71088.458%1830 RPM34.9 dB(A)43.70°C0.999
1041.890A9.063A8.995A3.084A599.66287.718%1860 RPM35.4 dB(A)44.83°C0.999
1146.829A9.071A9.014A3.090A659.59386.965%1870 RPM35.6 dB(A)46.07°C0.999
CL10.098A13.019A13.003A0.004A110.01881.865%1790 RPM34.5 dB(A)44.20°C0.993
CL249.948A1.005A1.002A1.002A622.14388.269%1850 RPM35.2 dB(A)44.58°C0.999

Load regulation on every rail except for 5VSB is pretty tight, and the PSU has no problem delivering more than its full power at high ambient temperatures.

That FDB fan spins quickly throughout our benchmark session, but its noise output isn't annoying, even during the full load and overload tests. Moreover, the SFX L Power 600W satisfies the 80 PLUS Gold efficiency requirements, despite our elevated ambient temperatures. Finally, we notice high power factor readings, meaning less energy goes wasted.

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Aris Mpitziopoulos
Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.