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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  • blahsaysblah - Saturday, April 8, 2017 - link

    Your math??

    Platinum only has guarantee for 20% and above, for a 850W PS at 20% load that is 170 Watts. Platinum guarantees 90% efficiency at 20% load so 170Watt load from PC would draw 189W at wall.

    Titanium adds a 10% load guarantee threshold of 90% efficiency, so a 850W PS need a 85W(95W at wall) load to 170W(185W at wall, titanium gives 92% at 20%) load.
  • Exodite - Friday, April 7, 2017 - link

    Any word on the pricing of the fanless 600W unit?

    I've been using a 400W fanless gold unit for quite some time and while I expect it to last many years still it's nice to have options.

    It's unfortunate, if understandable, that the high-end supplies come with such high wattages as efficiency suffers under low load scenarios.
  • oranos - Friday, April 7, 2017 - link

    seasonic #1
  • jabber - Friday, April 7, 2017 - link

    Isn't it time we moved to some newer and more compact power connectors for motherboards? The current selection are very 1980's.
  • JasperJanssen - Saturday, April 8, 2017 - link

    No, it really isn't time to move to more compact connectors. For the amount of power you need to transfer, it doesn't really get much more compact.
  • Byte - Sunday, April 9, 2017 - link

    That's what iMacs are for.
  • lordken - Saturday, April 8, 2017 - link

    you aren't really a tech guy are you?
    Don't fix whats not broken. Why change power connectors as they fulfill their purpose just good? What would be benefit of such more compact redesign? That they look better? lol give me a break
    And if it is disgrace for your sight to look at them, you only need to do it once when you build PC. Hope you can manage.

    Go and buy yourself new phone or fancy toy to satisfy your thirst for modernity...geez
  • surt - Sunday, April 9, 2017 - link

    There are also those niggly laws of physics to deal with.
  • robotmaster0 - Sunday, April 9, 2017 - link

    Funny you would say that since the 80's mainboard connectors (AT - 2x6pin Molex) were smaller then our big modern ones (ATX). Of course I would not want to be constrained to AT power requirements.
  • jpak725 - Saturday, April 8, 2017 - link

    if only seasonic made sfx psus of this quality

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