RelaxedTech Logo

Seasonic Focus Plus 850W Platinum PSU Review: As Good As It Gets For A High Quality PSU

Author: HP   Date:  Manufacture: Seasonic   Product Name: SSR-850PX   Price: $139.99   Warranty: 10 Years


Seasonic Focus Plus 850W Platinum PSU Review

Seasonic was founded in 1975 and they are the first manufacture to make power supplies for the PC industry. Since its inception, Seasonic has consistently released quality products and not only do they make their own PSUs, but they also make PSUs for companies like Corsair and EVGA. In the PC community, Seasonic is known as the best PSU brand and they are one of the few that makes and brands their own PSUs.

Seasonic’s Focus Plus series consists of the Gold and Platinum product line, with the Platinum line offering four power supplies ranging in capacity from 550W up to 850W while the Gold line goes all the way up to 1000W. Earlier this year we reviewed the Focus Plus 750W Gold and Focus FM 650W Gold which seriously impressed us with their amazing internal build quality and exceptional performance. Today we will be taking a detailed look at the Focus Plus 850W Platinum power supply. If you are looking to build a new system and don't know what power supply to buy, we strongly recommend you to look at the Seasonic's Focus Plus series or the Focus line if you want to save some money.

Pricing & Warranty

The Focus Plus 850W Platinum power supply retails for $140 on Amazon and comes with a 10 year warranty. This is an 80+ Platinum certified PSU which means that it is 92% efficient at 50% load. Seasonic's Focus Plus series feature an aggressive pricing which pushes its competitors to lower the price on their products. At $140, the SSR-850PX is about $20 to $40 cheaper compared to other 850W Platinum PSUs from other reputable manufactures such as Thermaltake, Enermax, Corsair and Antec. Before the Focus Plus series, Seasonic's products were known to have a high price-tag but we're happy to see Seasonic lower the price and make their products affordable for everyone.

Seasonic is one of the few companies that provides a 10 year warranty on their power supplies. The majority of the manufactures offer 5 year warranties so this shows Seasonic's commitment to their PSU quality and longevity. The SSR-850PX features a single +12V rail that can deliver up to 70A (840W) on the +12V output which is enough power to feed two high-end graphics cards and still have plenty of room for overclocking your CPU.


The Focus Plus 850W Platinum sports a fully modular design which allows you to use only the cables you need thus helping improve case airflow and eliminating unnecessary wires and reducing clutter. Seasonic is using high-quality Japanese brand capacitors that ensure long-term reliability. Another good thing about the Focus Plus 850W Platinum power supply is that it comes in a small 140mm footprint which can help in cases where space is premium.

Seasonic Focus Plus 850W Platinum PSU

Seasonic has equipped the Focus Plus 850W Platinum with a 120mm Fluid Dynamic Bearing (FDB) fan with the ability to run in three operational stages: Fanless Mode, Silent Mode, and Cooling Mode. There is a switch at the back of the power supply which allows users to customize their cooling needs by selecting between the S2FC (fan control without Fanless Mode) and the S3FC (fan control including Fanless Mode). The fan in the power supply turns off for silent operation during idle or low powered activities if the loading condition is below 30%. The Fluid Dynamic Bearing (FDB) fan is a high quality fan that is extremely reliable and generates considerably less operating noise and heat than ball bearing fans.

The Focus Plus 850W Platinum includes ±3% tight voltage regulation which helps significantly with stability. In other words, think of voltage regulation this way. When your computer is running, the current power draw can suddenly change for your CPU or GPU load. When this happens, the less change in voltage, the better thus resulting in better stability for your computer. Cheap power supplies don't do this very well, and can often damage the components of your computer so be very careful when purchasing some random power supply you find on websites such as Amazon and Newegg.

Seasonic Focus Plus 850W Platinum Power Supply Review

Most of the really good PSUs out there are rated for 50°C operating temperature but the majority of them are generally rated for 40°C. This is a pretty difficult standard to meet and Seasonic has achieved that with the Focus Plus series and the SSR-850PX comes with a 50°C operating temperature. Seasonic has also implemented a cable-free connection design solution where instead of cables, the back panel and the PCB are connected by a copper plate. This lowers the chance of production errors during manual insertion and also improves power efficiency.


Seasonic SSR-850PX Specifications
Max. DC Output:850W
Over Voltage Protection:Yes
Weight:6.80 lbs
Efficiency Level:ETA-A
Form Factor:Intel ATX 12 V
Dimensions:140 mm (W) x 150 mm (L) x 86 mm (H)
Fan Size:120 mm
Fan Control:Premium Hybrid Fan Control
Fan Bearing:Fluid Dynamic Bearing
Life Expectancy:50,000 hours at 40 °C, 15 % - 65 % RH
Modularity:Fully Modular
Cable type:Flat black cables
Operating Temperature:0 - 50 °C (derating from 100 % to 80 % from 40 °C to 50 °C)
MTBF @ 25 °C, excl. fan:100,000 hours
AC Input:Full Range
Protection:OPP, OVP, UVP, OCP, OTP, SCP
Safety and EMC:cTUVus, TUV, CB, CCC, BSMI, EAC, CE
Environmental Compliance:Energy Star, RoHS, WEEE, ErP Lot 6, REACH
Warranty:10 Years
Voltage:100 V - 240 V
Current:11 - 5.5 A
Frequency:50 Hz - 60 Hz
Load Range
Rail+3.3V+5V+12V-12 V+5 VSB
Max.(Amps):20 A20 A70 A0.3 A3 A
Max.(Power):100 W840 W3.6 W15 W
Total Continuous Power:850 W
Main Connector20+4Pin
+12V Rails:Single
PCI-Express Connector:4 x 6+2-Pin
SATA Power Connector:8
Connectors:1 x ATX connector 20+4 pin (610mm)
2 x 4/8 Pin CPU (650mm)
6 x 6+2 pin PCIe (675mm+75mm)
10 x SATA (450mm+120mm+120mm+120mm)
5 x Peripheral (450mm+120mm+120mm) / (350mm+120mm)
1 x FDD (101mm)


Seasonic Focus Plus 850W Platinum packaging box

The SSR-850PX comes in an attractive box that stands out when you first see it due to the silver white color. Looking at the front of the box, we see the Seasonic logo on the top left corner followed by the 'Focus+ Platinum' text in the center and '850PX' model number in the bottom right corner.

On the back, you will see a list of the SSR-850PX's features such as the 80Plus Platinum rating, DC to DC converter design, +12V output, tight voltage regulation, APFC (Active Power Factor Correction) which helps with reducing line loss and power distortion, highly reliable aluminum solid capacitors, 120mm FDB fan, compact design, fully modular cabling, and a 10-year warranty.

Seasonic Focus Plus 850W Platinum box

Seasonic's packaging is fantastic and I've never seen a company take packaging this seriously. We can see that the SSR-850PX is protected by two high density foams as shock absorbent to prevent any accidental damages during shipping. The power supply is enclosed inside a cloth bag that definitely gives it a premium feel to it. Most manufactures package their power supplies in plastic bags so it's nice to see Seasonic go the extra mile with their packaging. There's a void sticker on one of the corners of the PSU and tampering with the PSU of course voids the warranty.

Inside the box you will find a set of Velcro straps, four mounting screws, several zip ties, Focus case badge, an AC power cord, a user's manual and a bundle of modular cables in a separate cloth bag. The manual has all the information you need to know about the power supply such as how to set up your power supply and basic troubleshooting. Size-wise, the SSR-850PX is 140mm wide, 86mm tall and 150mm long and weighs 6.80 lbs.

Seasonic Focus Plus 850W Platinum cables

The cables are made of high quality materials and are of ample length. You can look at the table above for connector count and for cable lengths. There is nothing to complain about the length of the cables, as they are sufficiently long for all towers but the only thing that I don't like about them is that Seasonic has added capacitors to some of the cables (ATX, EPS, PCIe) for extra ripple filtering. Adding capacitors to these cables has made them quite bulky which makes the cables difficult to fold and route around the case but the peripheral cables don't have capacitors in them so they are flat. Flat cables have much greater flexibility to allow for tighter folding and management of cables.


comments powered by Disqus