Seasonic Focus Plus Gold 850 PSU Review

Seasonic rocked the boat with its Prime PSUs. Aside from ultra-high performance, they also come with a stunning 12-year warranty. This alone shows the level of confidence Seasonic has in its platform.

A step down from the Primes, Seasonic also has its affordable Focus family, available at a number of different capacity points. Today's review covers the Focus Plus Gold series' flagship, the SSR-850FX. We already reviewed the lower-end SSR-750FX and came to a positive conclusion, so we're expecting the same solid performance (if not better) from the 850W version.

Seasonic uses a new platform for its Focus family, built for performance on a budget. In other words, it's more value-oriented than the Prime models, which achieve better results, but also cost a lot more. Seasonic goes a step further and pushes its competitors with aggressive pricing on the Focus PSUs (the SSR-850FX lists for ~$110 and sells for roughly $100). That's a fairly new approach for Seasonic. Up until this family's introduction, the company was known for loftier price tags to match its solid benchmark numbers. We're glad to see that correlation coming to an end.

At this point, we don't know if Seasonic will offer this platform to other brands. More certain, though, is that the company wants to establish a retail presence and not rely so heavily on the OEM market. That means spending more money on support and putting in an effort to expand distribution. Should Seasonic maintain the SSR-850FX's current price, EVGA and Corsair will almost certainly need to respond. After all, at the time of this review, the Focus series' flagship sells at a similar level as EVGA's 850 B3, occupying a much higher performance category and doubling its warranty period.


Besides Gold-rated efficiency on the 80 PLUS scale, this PSU also carries Cybenetics' ETA-B and LAMBDA-B ratings. All necessary protection features are included, and cooling is handled by a 120mm FDB fan supported by a selectable semi-passive mode.

Finally, the PSU's dimensions are very compact thanks to its limited 140mm depth.

Power Specifications

Max. PowerAmps20207030.3
Total Max. Power (W)850

The minor rails only offer 100W maximum combined power, which looks low compared to other 850W PSUs. Don't worry, though: all modern PCs mainly use the +12V rail, and this PSU delivers up to 840W on that one. The 5VSB rail does have enough capacity, and its OCP is actually much higher than 3A.

Cables And Connectors

Modular Cables
DescriptionCable CountConnector Count (Total)Gauge
ATX connector 20+4 pin (610mm)1118-22AWG
4+4 pin EPS12V (655mm)2218AWG
6+2 pin PCIe (680mm+80mm) 3618AWG
SATA (460mm+115mm+115mm+115mm)2818AWG
SATA (460mm+115mm)1218AWG
Four-pin Molex (460mm+120mm+120mm)1318AWG
Four-pin Molex (360mm+120mm)1218AWG
FDD Adapter (+105mm)1122AWG

Seasonic gives us two EPS connectors and six PCIe ones, so the SSR-850FX can easily deliver its full capacity through a high-end motherboard and up to three potent graphics cards. The number of SATA and four-pin Molex connectors is sufficient as well. Our only criticism is the short distance between SATA and peripheral connectors, which ideally should be 15cm.

Power Distribution

Since this PSU features a single +12V rail, we do not have anything to say about its power distribution.

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