Founded over 35 years ago, Seasonic is one of the first PC power supply manufacturers and today their products are held in very high regard amongst PC enthusiasts. Despite their high popularity and recognition that the brand name has, the company is one of the very few that did not diversify towards other segments of the market. Seasonic is solely focused on the design, manufacturing and marketing of quality PC power supply units.

During the past several years, we reviewed several of Seasonic’s PSUs, including their latest 80Plus Gold and 80Plus Platinum series. Today we are having a look at their latest product series, the 80Plus Titanium certified PRIME. Seasonic designed the PRIME PSUs to offer the best possible performance and quality they could while keeping the price tag within reasonable limits. The series consists of five units, one fanless 600W model and four regular units with their maximum rated power output ranging from 650W to 1000W. In this review we are going to test three out of the five units of the series, the 650W, 750W and 850W versions. (It is worth noting that the 600W and 1000W versions not yet available to the North American markets, which is sometimes a limitation in our sampling.)

Model Price
Seasonic PRIME SSR-650TD $170 incl. shipping
Seasonic PRIME SSR-750TD $175 incl. shipping
Seasonic PRIME SSR-850TD $200 incl. shipping

Seasonic PRIME Titanium
Power specifications ( Rated @ 50 °C )
AC INPUT 100 - 240 VAC, 50 - 60 Hz
RAIL +3.3V +5V +12V +5Vsb -12V
650TD 750TD 850TD
MAX OUTPUT 20A 20A 54A 62A 70A 3A 0.3A
100W 648W 744W 840W 15W 3.6W
SSR-750TD: 750W
SSR-850TD: 850W


Packaging and Bundle

Seasonic kept their packaging very simple, elegant and functional. The artwork is limited to basic geometric shapes and metallic colors. Our early samples came with an error on the packaging as well - the PRIME units are covered by a 12-year warranty, not 10 years as indicated on our packaging. The packaging is very sturdy, with thick cardboard walls and polyethylene foam pieces protecting the product inside.

Inside the packaging, we found the necessary AC power cable, four typical 3M mounting screws, a good user’s manual, a few typical cable ties, five high-quality cable straps with the company logo, a metallic case badge, and a sticker. There were no thumbscrews or black screws included.

The PRIME PSUs are fully modular. Every cable, including the 24-pin ATX cable, is detachable from the chassis. With the exception of the 24-pin ATX cable that is enfolded in black nylon sleeving, the rest of the cables are “flat”, ribbon-like. All of the cables have black connectors and wires.

Connector Seasonic SSR-650TD Seasonic SSR-750TD Seasonic SSR-850TD
ATX 24 Pin 1 1 1
EPS 4+4 Pin 2 2 2
EPS 8 Pin - - -
PCI-E 6+2 Pin 4 4 6
PCI-E 8 Pin - - -
SATA 6 10 10
Molex 5 5 5
Floppy 1 1 1
External and Internal Design
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  • TEAMSWITCHER - Saturday, April 8, 2017 - link

    This site isn't nearly as useful as it once was....
  • Ian Cutress - Monday, April 10, 2017 - link

    Care to elaborate?
  • crashtech - Saturday, April 8, 2017 - link

    All these need is a Hobbs meter, they sound like a rock you can build many a system upon.
  • Stele - Sunday, April 9, 2017 - link

    Well-written review as usual, offering a good balance between technical detail and readability. I have however noticed that you use the term "primary conversion bridge" in your PSU reviews. I believe you're referring to the component which converts AC to DC; if so, it's properly called a "bridge converter". That aside, do keep up the good work!
  • surt - Sunday, April 9, 2017 - link

    In what country? Around here primary conversion bridge is definitely the correct term.
  • Stele - Monday, April 10, 2017 - link

    Actually in many if not most English-speaking countries. Countries aside - it's also used by the semiconductor industry, including manufacturers themselves. For just a few examples:-

    And in standard electronic texts - try Cedra & Smith, Microelectronic Circuits (any edition).

    I was an electrical engineer :)
  • Stele - Monday, April 10, 2017 - link

    I hasten to add my original post was itself erroneous - I meant to say "bridge rectifier" not "bridge converter". Not enough coffee!
  • mobutu - Sunday, April 9, 2017 - link

    The only thing I'm interested in from this series is the minimum wattage option, the 600W fanless.
    And also hope that seasonic will offer lower wattage also in this product line. (like 300-500W range)
    I'll never use more than one GPU so have no use for PSUs more than 500-600W, even overclocked.
  • Hxx - Monday, April 10, 2017 - link

    for the price they should have included paracord cables
  • Laststop311 - Monday, April 10, 2017 - link

    I have the 750 watt version and it's a work of art. Either than fan has never spun up or i cant hear it. Even with a 5.0ghz overclock 7700k cooled with a nh d15s and thermal grizzly liquid metal with the ultra low speed adapters for the fans. Inside a fractal define r5 with 2x 140mm venturi HF intake fans and 1x 140mm fractal exhaust that comes with it. controlled with asus fanxpert. System is dead quiet and powers everythng like a boss. paired with an rx 480 overclocked to the max since i have a free sync monitor. im happy with 144hz 1920x1080 gaming on a curved 27" acer predator. Thank you seasonic for making the best PSU ever made.

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