Seasonic Prime Ultra Titanium 1000W PSU Review: Quiet Dominance

Why you can trust Tom's Hardware Our expert reviewers spend hours testing and comparing products and services so you can choose the best for you. Find out more about how we test.

Efficiency, Temperature & Noise


Our efficiency testing procedure is detailed here.

Using results from the previous page, we plotted a chart showing the SSR-1000TR’s efficiency at low loads, and loads from 10 to 110 percent of its maximum-rated capacity.

The efficiency levels we measure are very high in every case.

Efficiency At Low Loads

In the following tests, we measure the SSR-1000TR'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.

Swipe to scroll horizontally
Test #12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan SpeedPSU NoisePF/AC Volts
11.197A0.491A0.478A0.196A19.65071.082%0 RPM<6.0 dB(A)0.829
22.418A0.989A0.988A0.396A39.76785.458%0 RPM<6.0 dB(A)0.913
33.640A1.485A1.500A5.007A59.88289.392%0 RPM<6.0 dB(A)0.949
44.851A1.993A1.982A0.796A79.81391.001%380 RPM9.6 dB(A)0.969

Under light loads, the efficiency levels we measure are very high and the PSU's noise is kept at minimal levels.

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.   

Swipe to scroll horizontally
Test #5VSBDC/AC (Watts)EfficiencyPF/AC Volts

The 5VSB rail is highly efficient.

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).

Swipe to scroll horizontally
Mode12V5V3.3V5VSBWattsPF/AC Volts

The SSR-1000TR's vampire power is very low with both voltage inputs.

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 36°C (96.8°F) to 46°C (114.8°F) ambient temperature.   

The next chart shows the cooling fan's speed (again, in RPM) and output noise. We measured acoustics from one meter away, inside a hemi-anechoic chamber. Background noise inside the chamber was below 6 dB(A) during testing (it's actually much lower, but our sound meter’s microphone hits its floor), and the results were obtained with the PSU operating at 36°C (96.8°F) to 46°C (114.8°F) ambient temperature. 

The following graph illustrates the fan's output noise over the PSU's operating range. The same conditions of the above graph apply to our measurements, though the ambient temperature was between 30°C (86°F) to 32°C (89.6°F).  

This chart clearly shows how quiet the SSR-1000TR is. Its passive mode doesn't last long, but the cooling fan spins slowly most of the time, minimizing its noise output.

MORE: Best Power Supplies

MORE: How We Test Power Supplies

MORE: All Power Supply Content

Aris Mpitziopoulos
Contributing Editor

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

  • jaber2
    Boy that is cheap
  • Nintendork
    I really wish companies focus on 300-550w Titanium PSU's, who the hell uses SLI/CF this days? Market is going multiCCX gpu's in the upcoming years.

    A Ryzen 2700X + Vega56/1070ti systems won't even draw past 375-400w. Most gaming PC's will stay at below 250w. Meanwhile for people who keep their PC 24/7 most of the time in idle, a contained PSU at titanium with 90% efficiency at 10% load is awesome.

    My Bronze Seasonic S12-II 520w seems to be a gem with 82% efficiency at 10% load when most higher grade PSU's (gold/platinum) ignore this since they only need to comply with 85-90% minimum @20% load and then crapify to hell once you reach 15-10% load.
  • Armando_0818
    Just an FYI. CISPR 22 is no longer used. It has been updated to CISPR 32.

  • Aris_Mp
    Thank you! The limits are the same though for the conducted emissions that we measure and in general the products that pass the CISPR22 are likely to pass testing against CIPSR32.

    The CISPR22 was for information technology equipment while CIPSR32 is for multimedia stuff in general.
  • zodiacfml
    Would you mind reviewing crypto PSUs from China? I have this Senlifang 2000W with 95 PLUS Gold sticker on it.
    I don't expect such efficiency until one day I plugged it to a system which previously has an 80 Plus Bronze - 650W PSU. The consumption on both PSUs are almost the same!
    Adding to that, I've read somewhere that it is easier to have higher efficiencies on high wattage PSUs which I guess adds more credibility to the Senlifang PSU efficiency claims.
  • Aris_Mp
    I don't believe that any of those manufacturers would be willing to send a review sample to me (or to any other PSU reviewer with proper equipment). The majority of them sell overrated stuff using bogus labels. Just be extra careful with those unknown PSU brands promising super high efficiency and wattage.