Skip to main content

Seasonic Prime Ultra Titanium 1000W PSU Review: Quiet Dominance

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.

Image 1 of 8

Image 2 of 8

Image 3 of 8

Image 4 of 8

Image 5 of 8

Image 6 of 8

Image 7 of 8

Image 8 of 8

Hold-Up Time

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

Image 1 of 7

Image 2 of 7

Image 3 of 7

Image 4 of 7

Image 5 of 7

Image 6 of 7

Image 7 of 7

The hold-up time we measure is longer than 17ms, while the power-good signal is accurate.

Inrush Current

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

Image 1 of 2

Image 2 of 2

The inrush current is at normal levels with both voltage inputs.

Load Regulation And Efficiency Measurements

The first set of tests reveals the stability of the voltage rails and the SSR-1000TR’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 SpeedPSU NoiseTemps (In/Out)PF/AC Volts
16.408A1.995A1.980A1.001A99.84791.856%395 RPM10.5 dB(A)38.63°C0.975
213.832A2.985A2.975A1.201A199.71593.543%395 RPM10.5 dB(A)39.27°C0.989
321.615A3.487A3.487A1.401A299.89993.945%395 RPM10.5 dB(A)39.54°C0.995
429.382A3.991A3.970A1.605A399.74393.518%435 RPM10.7 dB(A)39.82°C0.995
536.813A4.983A4.964A1.806A499.63692.971%310 RPM9.4 dB(A)40.53°C0.994
644.250A5.985A5.961A2.010A599.61892.354%430 RPM10.8 dB(A)41.83°C0.994
751.682A6.992A6.961A2.210A699.56691.687%525 RPM13.8 dB(A)42.08°C0.995
859.117A7.991A7.960A2.416A799.45590.960%625 RPM19.5 dB(A)43.20°C0.996
966.981A8.488A8.479A2.416A899.41290.196%1005 RPM32.0 dB(A)44.10°C0.997
1074.610A9.001A8.968A3.030A999.38189.252%1525 RPM42.8 dB(A)45.00°C0.997
1182.811A9.005A8.966A3.031A1099.17888.448%1650 RPM45.8 dB(A)46.15°C0.997
CL10.100A15.021A15.005A0.005A126.58888.385%540 RPM15.8 dB(A)43.61°C0.982
CL282.929A1.002A1.003A1.002A1024.40389.427%1490 RPM42.6 dB(A)44.70°C0.997

All of the rails offer great load regulation. However, Seasonic's SSR-1000PD registers better overall performance in this section. Frankly, we're not surprised. Since the SSD-1000TR emphasizes efficiency, compromises had to be made in other areas.

Speaking of efficiency, the 80 PLUS Titanium threshold is met with 10% load, and the same goes for 20% load. With 50% and 100% load, this PSU doesn't satisfy the Titanium certification's requirements. Then again, we also test at much higher ambient temperatures than 80 PLUS, so our results are expected. Regardless, this is still one of the most efficient 1kW PSUs.

Noise output remains low up to the 80% load test, and as you can see, the fan's speed drops with a 50% load. This happens because the fan starts spinning fast initially, and as its voltage input increases up to a certain threshold, speed decreases. Seasonic's trick allows for a low start-up fan voltage.

MORE: Best Power Supplies

MORE: How We Test Power Supplies

MORE: All Power Supply Content

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