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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  • nagi603 - Friday, April 7, 2017 - link

    Let's hope their eventual redesign won't be as bad as the X-series redesign was. I've had two fail (1 blew on first power-on, the other after half a year) while my original X-400 is still happy as ever after running out of its warranty, regularly driving ~400W of components.
  • Freakie - Saturday, April 8, 2017 - link

    In contrast, my 2nd gen X-750 has run like a champ for the last 4 years. My system also doesn't pull more than 450W so I keep the PSU power draw in the sweet spot which is why I got the 750W instead of the 650W.
  • feelingshorter - Saturday, April 8, 2017 - link

    I had the X-650, bought when it first came out in 2010 and used it in a computer that i rarely turned off until Jan of 2017 when I sold it. I payed $120 for mine at the time. But the competition is stiff and people are price sensitive, they do not want to hear why they need a PSU that expensive. I can imagine the company had to find ways to reduce costs on the X series, resulting in failures.

    I believe the PRIME Titanium series offered here represents the best the company can offer and we already know the company can produce a quality product, and quality costs money. The PRIME Titanium, at $160 shipped represents what the X Series was when it first came out.
  • azazel1024 - Friday, April 7, 2017 - link

    They certainly appear to be awesome power supplies. I just wish someone would focus on the low power market for ATX power supplies. I realize as a heavy user, my rigs are rather lightweight, mostly because I have heavy use, but not rigorous gaming. My Desktop running a GTX750 and i5-3570@4GHz sips 122w with an Antec Earthwatts PSU under both gaming and Handbrake loads. I could probably push it up over 140 or 150w with something like furmark, but that doesn't represent a realistic load case. That is with a couple of HDDs, an SSD, 16GB (4x4) GB or DDR3 1866. No, not the most ridiculous system ever, but even if I slapped in something like a 1060 or whatever it is doubtful I'd push the system beyond about 250w.

    My server is running a Celeron G1610, an SSD and a couple of HDDs with 8GB of DDR3 (2x4GB) and an Intel ET GbE adapter. It sips 19w at idle with the drives spun down, 31w streaming to my AppleTV with the HDDs spun up and about 50w under max CPU load all with a Seasonic SSR-360GP.

    Realistically most gamers probably don't even need something with more than about 400w of delivered power and most mainstream users/systems are looking at <200w peak. For some of these lightweight builds it would be really, really nice to see some high efficiency systems in ATX form factors that were targeted more at 100-200w range.

    Even my Seasonic SSR-360gp as nice as it is, only manages about 75% efficiency at 19w and its power factor is about .72-.74
  • mjeffer - Friday, April 7, 2017 - link

    While I agree 100%, it would be really nice to see some extremely high quality, lower wattage PSU, from my understanding it's a lot easier for them to hit higher efficiency ratings with higher power PSUs. However, I'd sacrifice the titanium efficiency for a lower power supply with the same top notch components throughout. I'd even pay good money for it. Sadly anything around 400W-500W is generally more focused on price than quality though some of the OEMs like Seasonic do make better ones in that range than you can find in your other brands.
  • Mr Perfect - Saturday, April 8, 2017 - link

    Yeah, it's the same thing down in the mITX space. My i7 + 1060 ITX is only pulling ~120ish watts while gaming. Something in the lower wattage range, and preferably in a SFX form factor, would be well suited. Other companies make them, but not in Seasonic's quality range.

    If I remember correctly, a Seasonic rep used to post comments on reviews of their products here, and he stated that they couldn't source 80+ Gold quality capacitors that would fit in SFX PSUs. I wonder if that's changed in the last few years.
  • SkipPerk - Wednesday, May 3, 2017 - link

    I want to say that Enermax and Seasonic have high-end 400W units that are platinum rated. They are not cheap, but they are really nice. I want to say I saw a review of them compared, but I forgot where. Many of the high-end low power systems are fanless.
  • Chapbass - Friday, April 7, 2017 - link

    These units seem really cool, but the thing I really want to see is the 600w fanless unit. Wanted a fanless power supply for a long time.
  • bji - Friday, April 7, 2017 - link

    I understand your point of view, as I also appreciate fanless. However, just keep in mind that very few builds are going to stress these power supplies to a point where they'll even turn the fan on. I have a Seasonic 650W from years ago and I am not sure the fan has ever even spun up.
  • JasperJanssen - Saturday, April 8, 2017 - link

    Keep in mind the 600W fanless is probably just the 1000W model, minus the fan. Or maybe one of the others, but either way, it'll just literally be one of the other models minus the fan. *Possibly* with larger heatsinks, but I wouldn't count on it.

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