Seasonic Prime Ultra Platinum 1000W PSU Review

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Teardown & Component Analysis

Before proceeding with this page we strongly encourage you to a look at our PSUs 101 article, which provides valuable information about PSUs and their operation, allowing you to better understand the components we're about to discuss. Our main tools for disassembling PSUs are a Thermaltronics soldering and rework station and a Hakko FR-300 desoldering gun. Finally, for the identification of tiny parts we use an Andonstar HDMI digital microscope.

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General Data
Manufacturer (OEM)Seasonic
Platform ModelPrime Ultra Platinum
Primary Side
Transient Filter6x Y caps, 3x X caps, 2x CM chokes, 1x MOV
Inrush ProtectionNTC Thermistor & Relay
Bridge Rectifier(s)2x Vishay LVB2560 (600V, 25A @ 105°C)
APFC MOSFETs2x Infineon IPP60R125CP (650V, 16A @ 100°C, 0.125Ω)
APFC Boost Diode1x CREE C3D08060A (600V, 8A @ 152°C)
Hold-up Cap(s)1x Nippon Chemi-Con (400V, 450uF, 2000h @ 105°C, CE) 1x Hitachi (400V, 820uF, 2000h @ 105°C, HU)
Main Switchers4x Infineon IPP50R250CP (550V, 9A @ 100°C, 0.25Ω)
Drivers For Main Switchers2x Silicon Labs Si8230BD
APFC ControllerON Semiconductor NPC1654
Switching ControllerChampion CM6901
TopologyPrimary side: Full-Bridge & LLC Resonant Converter Secondary side: Synchronous Rectification & DC-DC converters
Secondary Side
+12V MOSFETs4x Fairchild FDMS015N04B (40V, 100A @ 25°C, 1.5mΩ)
5V & 3.3VDC-DC Converters: 6x Infineon BSC0906NS PWM Controller: APW7159
Filtering CapacitorsElectrolytics: Nippon Chemi-Con (105°C, W), Nippon Chemi-Con (4000-10,000h @ 105°C, KY), Rubycon (6000-10,000h @ 105°C, ZLH), Nichicon (4000-10,000h @ 105°C, HE), 1x Rubycon (5VSB circuit, 105°C, YXD) Polymers: FPCAP, Nippon Chemi-Con
Supervisor ICWeltrend WT7527V (OVP, UVP, OCP, SCP, PG ) & AS393M
Fan ModelHong Hua HA13525H12F-Z (135mm, 12V, 0.50A, 2000 RPM, Fluid Dynamic Bearing)
5VSB Circuit
Buck ConverterLeadtrend LD7750R
RectifiersSTMicroelectronics STU6N65K3 (650V, 3A @ 100°C, 1.3Ω) Infineon BSC0906NS(30V, 40A @ 100°C, 4.5mΩ)
-12V Circuit
Buck ConverterLite-On LSP5523 (3A max output current)

The Prime Ultra platform looks identical to the non-Ultra platform, just as we expected. One thing is for sure, though: the new PSU's fan profile is different. As a result, all Prime Ultra models feature much quieter operation than their predecessors. This is a major advancement for enthusiasts looking to build high-end PCs that don't make a lot of noise. Seasonic's engineers apparently took the safe road for its Prime Platinum and Gold units, tuning fan speeds aggressively. Along the way, they realized they went too far, giving us the SSR-1000PD Ultra's looser fan curve.

A full-bridge topology is used on this PSU's primary side, along with an LLC resonant converter. That's typical for high-efficiency circuits able to satisfy the toughest efficiency requirements from both 80 PLUS and Cybenetics. On the secondary side, FETs regulate the +12V rail, while a couple of VRMs handle the minor rails.

Build quality is top-notch and the design is clean. There's enough space around the main PCB's components to allow for optimal airflow, which is enhanced by a lack of cabling inside the chassis. Given the SSR-1000PD Ultra's compact dimensions and 1kW capacity, it's impressive that the main PCB isn't densely populated with components.

The following video shows the SSR-1000PD Ultra’s internals.

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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.