Seasonic Prime Ultra Platinum 1000W PSU Review

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.

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.

Latest Videos FromTom's Hardware

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 # 12V 5V 3.3V 5VSB DC/AC (Watts) Efficiency Fan Speed PSU Noise Temps (In/Out) PF/AC Volts
1 6.380A 1.984A 1.974A 0.997A 99.798 90.184% 0 RPM <6.0 dB(A) 44.09°C 0.977
12.263V 5.028V 3.341V 5.005V 110.661 38.19°C 115.07V
2 13.767A 2.978A 2.961A 1.199A 199.691 92.534% 0 RPM <6.0 dB(A) 44.94°C 0.985
12.264V 5.026V 3.340V 5.000V 215.804 38.82°C 115.05V
3 21.509A 3.486A 3.471A 1.401A 299.905 93.037% 0 RPM <6.0 dB(A) 45.47°C 0.986
12.265V 5.024V 3.338V 4.994V 322.351 39.19°C 115.05V
4 29.237A 3.983A 3.953A 1.601A 399.749 92.918% 605 RPM 22.2 dB(A) 39.49°C 0.991
12.264V 5.022V 3.338V 4.989V 430.215 48.96°C 115.05V
5 36.631A 4.978A 4.945A 1.805A 499.684 92.545% 605 RPM 22.2 dB(A) 40.08°C 0.994
12.263V 5.020V 3.335V 4.984V 539.935 50.75°C 115.05V
6 44.018A 5.976A 5.934A 2.006A 599.608 91.985% 660 RPM 23.8 dB(A) 40.83°C 0.995
12.264V 5.019V 3.335V 4.979V 651.856 51.71°C 115.06V
7 51.409A 6.980A 6.928A 2.211A 699.596 91.272% 1108 RPM 34.0 dB(A) 41.42°C 0.996
12.264V 5.017V 3.334V 4.975V 766.498 52.57°C 115.07V
8 58.804A 7.972A 7.921A 2.412A 799.473 90.389% 1727 RPM 44.6 dB(A) 42.32°C 0.997
12.263V 5.015V 3.332V 4.970V 884.481 53.72°C 115.07V
9 66.609A 8.475A 8.431A 2.414A 899.484 89.466% 2132 RPM 51.7 dB(A) 43.34°C 0.997
12.264V 5.015V 3.332V 4.970V 1005.392 55.12°C 115.08V
10 74.163A 8.982A 8.919A 3.026A 999.316 88.573% 2132 RPM 51.7 dB(A) 45.09°C 0.998
12.265V 5.012V 3.330V 4.953V 1128.242 57.13°C 115.08V
11 82.302A 8.987A 8.921A 3.029A 1099.234 87.456% 2132 RPM 51.7 dB(A) 47.06°C 0.998
12.266V 5.010V 3.329V 4.950V 1256.902 59.39°C 115.08V
CL1 0.099A 15.020A 15.003A 0.005A 127.005 87.375% 726 RPM 26.0 dB(A) 43.59°C 0.988
12.260V 5.027V 3.350V 5.053V 145.356 49.78°C 115.09V
CL2 82.937A 1.001A 1.004A 1.002A 1030.663 88.346% 2132 RPM 51.7 dB(A) 45.81°C 0.998
12.266V 5.013V 3.326V 4.991V 1166.615 55.46°C 115.09V

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.


MORE: Best Power Supplies


MORE: How We Test Power Supplies


MORE: All Power Supply Content

TOPICS
Aris Mpitziopoulos
Contributing Editor

Aris Mpitziopoulos is a contributing editor at Tom's Hardware, covering PSUs.

  • Th_Redman
    I notice you didn't give it an award rating...what gives, if you present it with such high praise?
    Reply
  • Aris_Mp
    It has an award. It is just not shown, yet :)
    Reply
  • 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.
    Reply