Seasonic Prime Ultra Platinum 1000W PSU Review

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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. 

Primary Rails And 5VSB Load Regulation

Load Regulation testing is detailed here.

Hold-Up Time

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

The hold-up time we measure lasts more than 31ms. And the power-good signal is pretty long as well. Plus, it's accurate.

Inrush Current

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

The registered inrush current with 115V is very low, while it's normal with 230V (given this PSU's high-capacity bulk caps).

Load Regulation And Efficiency Measurements

The first set of tests reveals the stability of the voltage rails and the SSR-1000PD Ultra'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.

Swipe to scroll horizontally
Test #12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan SpeedPSU NoiseTemps (In/Out)PF/AC Volts
16.380A1.984A1.974A0.997A99.79890.184%0 RPM<6.0 dB(A)44.09°C0.977
213.767A2.978A2.961A1.199A199.69192.534%0 RPM<6.0 dB(A)44.94°C0.985
321.509A3.486A3.471A1.401A299.90593.037%0 RPM<6.0 dB(A)45.47°C0.986
429.237A3.983A3.953A1.601A399.74992.918%605 RPM22.2 dB(A)39.49°C0.991
536.631A4.978A4.945A1.805A499.68492.545%605 RPM22.2 dB(A)40.08°C0.994
644.018A5.976A5.934A2.006A599.60891.985%660 RPM23.8 dB(A)40.83°C0.995
751.409A6.980A6.928A2.211A699.59691.272%1108 RPM34.0 dB(A)41.42°C0.996
858.804A7.972A7.921A2.412A799.47390.389%1727 RPM44.6 dB(A)42.32°C0.997
966.609A8.475A8.431A2.414A899.48489.466%2132 RPM51.7 dB(A)43.34°C0.997
1074.163A8.982A8.919A3.026A999.31688.573%2132 RPM51.7 dB(A)45.09°C0.998
1182.302A8.987A8.921A3.029A1099.23487.456%2132 RPM51.7 dB(A)47.06°C0.998
CL10.099A15.020A15.003A0.005A127.00587.375%726 RPM26.0 dB(A)43.59°C0.988
CL282.937A1.001A1.004A1.002A1030.66388.346%2132 RPM51.7 dB(A)45.81°C0.998

Load regulation on the +12V rail is jaw-dropping! The other rails are pretty awesome as well, but they don't quite hit that +12V rail's superb levels.

When it comes to efficiency, Seasonic's SSR-1000PD Ultra satisfies the 80 PLUS Platinum certification's requirements with 20% and 50% load, but falls short under full load. Of course, we perform this test at high ambient temperatures, whereas 80 PLUS benchmarks at room temperature (23°C +/-5°C).

The fan profile is relaxed up to our 60% test. But once the load hits 80% of this PSU's maximum-rated capacity and the ambient exceeds 42°C, the fan starts spinning very fast, generating lots of noise. Under full load, the fan is disturbingly loud, reaching 52 dB(A). At that point, it's difficult to tolerate. We should note, though, that during those final load tests (9-11), we're pushing our test subject hard in a hot environment. It's only natural that the fan kicks in to keep the internal temperature as low as possible to prolong the PSU's useful life.

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Contributing Editor

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

  • Th_Redman
    I notice you didn't give it an award rating...what gives, if you present it with such high praise?
  • Aris_Mp
    It has an award. It is just not shown, yet :)
  • Kennyy Evony
    Lets all hope it doesn't kill your motherboard and all components like my SeaSonic did while only operating 1 year under light workloads. No matter how much change they make to PSU I would not trust a brand that would allow catastrophic results in using their products AND not accept responsibility for the loss.