Seasonic Prime Titanium Fanless 600W PSU Review

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Efficiency, Temperature & Noise


Our efficiency testing procedure is detailed here.

Using results from the previous page, we plotted a chart showing the SSR-600TL's efficiency at low loads, and loads from 10 to 110 percent of its maximum-rated capacity.

The PSU's efficiency is very high under both light and normal loads.

Efficiency At Low Loads

In the following tests, we measure the SSR-600TL's efficiency at loads significantly lower than 10 percent of its maximum capacity (the lowest load the 80 PLUS standard measures). The loads we dialed were 20, 40, 60, and 80W. This is important for representing when a PC is idle, with power-saving features turned on.

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Test #12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan SpeedPSU NoisePF/AC Volts
11.171A0.491A0.476A0.199A19.30479.277%0 RPM<6.0 dB(A)0.779
22.427A0.991A0.985A0.398A39.79586.688%0 RPM<6.0 dB(A)0.904
33.610A1.486A1.464A5.026A59.30589.879%0 RPM<6.0 dB(A)0.944
44.860A1.984A1.973A0.797A79.71591.769%0 RPM<6.0 dB(A)0.965

With 20W load, the PSU's efficiency is close to 80%! This is something we rarely see, despite the large number of samples that pass through our lab.

5VSB Efficiency

The ATX specification, along with CEC, ErP Lot 3 2014 and ErP Lot 6 2010/2013, states that 5VSB standby supply efficiency should be as high as possible, recommending 75 percent or higher with 550mA, 1A, and 1.5A of load. The PSU should also achieve higher than 75% efficiency at 5VSB under full load, or with 3A if its max current output on this rail is higher than 3A.

We take six measurements: one each at 100, 250, 550, 1000, and 1500mA, and one with the full load the 5VSB rail can handle.

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Test #5VSBDC/AC (Watts)EfficiencyPF/AC Volts

The 5VSB rail is highly efficient, matching the SSR-600TL's overall performance.

Power Consumption In Idle And Standby

In the table below, you'll find the power consumption and voltage values of all rails (except -12V) when the PSU is idle (powered on, but without any load on its rails), and the power consumption when the PSU is in standby mode (without any load, at 5VSB).

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Mode12V5V3.3V5VSBWattsPF/AC Volts

This PSU consumes low energy levels at idle, something that really helps the 5VSB rail's efficiency, especially under light loads.

Fan RPM, Delta Temperature, And Output Noise

Our mixed noise testing is described in detail here.

The first chart below illustrates the cooling fan's speed (in RPM), and the delta between input and output temperature. The results were obtained at 37°C (98.6°F) to 45°C (113°F) ambient temperature.   

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Aris Mpitziopoulos
Contributing Editor

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