XFX Pro Series 850W Black Edition PSU - Introduction

XFX is a company which became widely known amongst computers users for their GFX card solutions. However, like many other companies, XFX also diversified into the PSU market a couple of years ago. Since several other companies had the same idea, the competition in the PSU market today is intense and each manufacturer is trying to entice the crowds with special designs and features. Today we are having a close look at the XFX Pro Series 850W Black Edition power supply, the successor of the XFX Pro Series 850W unit which has been replaced early this year.

XFX Pro Series 850W Black Edition

The XFX Pro Series 850W that we will be reviewing today is the successor of the 2011-2012 model, which was sharing the exact same name. The “Black Edition” suffix indicates that the unit which we will be reviewing today is the brand new 2013 model. It has a very long list of features, the most basic of which probably are the single 12V voltage rail, the 80Plus Gold efficiency certification and the fully modular design. With a very reasonable retail price of $140.78 shipped (after rebate) from Newegg or $149.99 shipped from Amazon, the new Pro Series 850W power supply seems like quite a good deal already. Read on as we find more about the quality and performance of this unit.

 XFX Pro Series 850W Black Edition Fan Grill

XFX Pro Series 850W Black Edition Features and Specifications


+12V Rail Outputs


ATX12V 2.2 & ESP12V 2.91 Compliant


Maximum Wattage (W)


Performance Category


UPC Number



CrossFire Ready


SLI Ready


Ratings & Efficiencies

AC Input Current (Arms)

11A - 5.5A

AC Input Frequency (Hz)

50/60 Hz

AC Input Voltage (Vac)

100 - 240

Active Power Factor Correction (PFC)

>0.95 at full load

DC Output Voltage Regulation


Efficiency @ Typical Load

up to 90%


80 Plus Gold Certified

Other Features

DC to DC Converters (+3.3 & +5V)


EZ Grip Connectors


High Reliable 105°C Japanese Capacitors


Solid State Capacitors


Active Power Factor Correction (PFC)


Haswell Compatibility


Load Range

+12V1 (mW)


Max -12V Output Current (A)


Max -12V Power (W)


Max +12V1 Output Current (A)


Max +12V1 Power (W)


Max +3.3V & +5V Combined Power (W)


Max +3.3V Output Current (A)


Max +5V Output Current (A)


Max +5VSB Output Current (A)


Max +5VSB Power (W)


Max. +3.3V & +5V combined power (W)


Wattage (W)


Safety & Protection

Over Current Protection (OCP)


Over Power Protection (OPP)


Over Temperature Protection


Over Voltage Protection (OVP)


Short Circuit Protection (SCP)


Under Voltage Protection (UVP)


Certifications & Standards







Unboxing the XFX Pro Series 850W Black Edition

The box

XFX supplies their premium power supply inside a large, strong cardboard box. The artistic theme is very basic, based on a picture of the power supply itself inside an austere geometric abstract design formed by many small cubes.

The box (rear)

The rear of the box is rather light, especially when compared to the massive marketing hype lists we are used to seeing on most boxes. This time there is only a detailed picture of the power supply itself and a strong focus on its most important features, only in English.

Bundled items

Aside from the typical manual and mounting screws, XFX provides two AC power cables, one for the US and one for the UK markets. We are unsure if that is because we received a sample for testing it on both voltages or if every such power supply comes with two ΑC cables but 99.999% of the users will definitely need only one.

As this is a fully modular power supply, XFX provides the modular cables in a simple, flat cardboard box. All of the wires and connectors are black and all of the cables are flat, ribbon-like, with the exception of the 24-pin ATX cable which is the only one inside a black sleeve. 

External Design of the XFX Pro Series 850W Black Edition

The XFX Pro Series 850W Black Edition PSU

The XFX Pro Series 850W Black Edition is physically similar to any other ATX-compliant power supply; with the exception that it has not a single cable hardwired to it. At 160mm deep, it is a little bit longer than the ATX design recommendation limit but should fit inside almost every ATX tower case currently available, unless it is a very old or proprietary design. The chassis is sprayed with a satin black paint and the fan grill is octagonal.

Side stickers

Decorative stickers cover both sides of the power supply. The black stickers only feature the company and series logos, however their shape makes them far more attractive than simple rectangular stickers.

Top side sticker

XFX must have a thing for geometric shapes with sharp edges, as even the sticker with the electrical specifications at the top side of the chassis is not a simple rectangle. This sticker will be visible through a windowed side panel if the case has the PSU compartment at its bottom; however, the sticker will be facing the rear of the case, away from the spectator.

Rear Side

As this is a fully modular design, it was expected that the rear side of the chassis would be littered with connectors for the modular cables. The connectors are split into two levels: the top level consisting of five Molex/SATA connectors and a single PCI Express/EPS 12V connectors, while the bottom level only has five PCI Express/EPS 12V connectors. The 24-pin ATX cable is split between both levels. If all of the cables are connected, the XFX Pro Series 850W Black Edition provides a total of two 12V connectors (one 8-pin EPS and one 4+4 pin ATX), six 6+2 pin PCIe connectors, five Molex connectors and ten SATA connectors. Two Molex-to-floppy adapters are also included.

One of the most important features of this power supply is the small switch which can be seen at the top right corner. This switch can be used to set the fan control to either "normal" or "hybrid". When in hybrid mode, the fan is generally quieter and will even stop when the unit's load is very low, while the normal mode sets a profile more aggressive towards cooling.

Front Side

The front side of the XFX Pro Series 850W Black Edition power supply is based on the standard perforated honeycomb mesh design, with only the standard on/off switch and power plug receptacle to be found. A sticker with the company logo has been attached right over the AC plug and switch.

Inside the XFX Pro Series 850W Black Edition

The cooling fan

An ADDA AD1212MB-A70GL 120mm fan is responsible for the cooling needs of this power supply. ADDA is a reputable manufacturer, the fans of which are cooling a large percentage of the power supplies available today. This particular model has a ball bearing and a maximum speed of 2050RPM.

Inside the XFX Pro Series 850W Black Edition unit

When we removed the cover of the XFX Pro Series 850W Black Edition, we encountered a very familiar sight. Seasonic is the OEM behind this power supply and it is based on one of their most popular platforms, the KM. The build quality is exceptional, with an immaculate soldering job and well-secured components.

The filtering stage

A small PCB, which has been shielded inside a metallic cage in order to minimize EMI interference, is attached on the rear of the AC receptacle and holds part of the filtering stage. In total, XFX installed six Y capacitors, three X capacitors, three chokes and a MOV, forming a very effective transient filter.

Primary side

The XFX Pro Series 850W Black Edition is using two parallel bridges to rectify the household AC voltage, which bridges have their own heatsink sandwiched between them. The APFC components consist of two Nippon Chemi-Con 420V/330uF 105°C capacitors, a large filtering coil, two transistors and a diode. The active components of the APFC are attached onto the large heatsink near the edge of the PCB. The smaller heatsink towards the main transformer holds the four inversion transistors which are forming a full bridge topology.

Secondary side

The secondary side of this power supply is very interesting, as it is making use of an advanced LLC rectifier design. The primary components of the rectifier are on the PCB next to the main transformer and the rectification transistors are attached on the U-type heatsink right next to it. The electrolytic capacitors are all provided by Nippon Chemi-Con. There are also many solid-state capacitors onto the vertical PCB for additional filtering, which are all made by Enesol. DC to DC conversion takes place directly onto the vertical PCB which holds the modular cable connectors.

Test Setup

The load


In order to be able to effectively and efficiently test any computer power supply unit, we developed and constructed our own proprietary testing station. Our testing station consists of a number of power resistors and small capacitors, which in turn are connected to a RS485 electronic relay array which allow our load to be controlled through computer software alone.


USB interface and connection panel


When accuracy and speed are of critical importance, a simple multimeter or voltage meter is not sufficient for the task. To ensure the quality of our testing, an USB laboratory interface is being used to continuously monitor and record the readings of all voltage lines simultaneously. For ripple measurements, an oscilloscope is necessary and we chose the USB Instruments Stingray, the most widely used oscilloscope amongst low voltage PSU engineers and testers.


Measurement instruments


For accurate testing and repeatable results, a stable power input is also required. Thus, we are providing power to our test samples through a 3kVA VARIAC which allows us to control the input voltage of our test samples and also perform efficiency tests under both 110V AC and 230V AC input. A Lutron DW-6091 is also being used, monitoring the input voltage, real and apparent power, power factor and amperage.


The software


A power supply testing procedure would not be complete without thermal and acoustics tests. For our acoustics tests we are using a SL-5868P digital sound level meter, placed 1 meter away from the unit (DIN standard). Two PT100 sensors and their respective displays are being used to monitor the ambient temperature and the exhaust temperature of the unit.


Complete test setup during trial run



Testing results (Regulation & Ripple)

The electrical performance of the XFX Pro Series 850W Black Edition is by all means excellent. Voltage regulation is very good, at about 1.5% for all three voltage lines between the minimum and maximum load range. Ripple filtering is excellent as well, with our system recording a maximum ripple of only 30mV on the 12V line under maximum load, a mere quarter of the 120mV design limit.

Testing results (Efficiency, Noise & Thermal)


The XFX Pro Series 850W Black Edition easily complies with its 80Plus Gold efficiency certification when powered by either an 110VAC or 230VAC source. In the former case, the maximum efficiency reaches up to 91.6% under 50% load and a minimum of 89.4% under maximum load. If the source voltage is at 230VAC, the efficiency is boosted by about 1% across the entire load range, reaching up to 92.5% under 50% load and falling as low as 90.2% under maximum load.

Below 30% load, the cooling fan of the XFX Pro Series 850W Black Edition will not operate at all, which is why we have no reading below this point. At 30% load the fan starts and remains entirely quiet up to 40% load. At 50% load, the sound coming from the fan becomes discernable, even if only barely. If the load surpasses 70% however, the noise becomes clearly noticeable and the noise levels continue to rise as the load increases. However, such a load suggests that at least two powerful GFX cards are giving it their all, therefore it is unlikely for the user to notice the noise for the obvious reasons.


Despite the high power output, the efficiency of the XFX Pro Series 850W Black Edition is high enough to keep the energy losses low. As a result, we have a very cool-running power supply which can maintain very low operational temperatures, with the temperature delta being about 6 °C across most of the range and reaching up to 10.2 °C under maximum load.

XFX Pro Series 850W Black Edition PSU Review Conclusion

Cooling Fan

Overall, the XFX Pro Series 850W Black Edition is not the best performing 850W power supply that we have ever tested, nor the most innovative, or the lowest priced; however, it is outstandingly balanced in every aspect. The overall performance is undeniably excellent, with the PSU easily conforming to the 80Plus Gold certification standards, running silent and maintaining low temperatures, as well as displaying admirable electrical performance. When it comes to quality, the fact that Seasonic is the OEM behind its manufacturing alone should be enough to satisfy even the most demanding of users. The choice of components is excellent, as is the quality of the assembly. XFX covers this unit with a 5 year warranty (parts + labor), which should be enough to quell any concerns.


Seasonic M2 Design

Aesthetically, the XFX Pro Series 850W Black Edition PSU is definitely one of the most interesting choices within its price range. The sharp design and the fully modular configuration with the black cables give it a considerable edge over many other products of similar power output and or price. Speaking of price, the Pro Series 850W Black Edition currently retails for $140.78 shipped after rebate. This is very competitive considering that the Seasonic X series retails for $169.99 shipped, which is $30 more and is based on the exact same design. We could go as far as calling the XFX Pro Series 850W Black Edition PSU a “mini” Corsair AX860, which we reviewed several months ago. The AX860 is but an advanced version based on the same platform with higher efficiency and performance and retails for $161.49 shipped, a $22 price premium that some might be willing to pay. All of these power supplies are great and based off the same core design, but the XFX Pro Series 850W PSU stands our from the crowd by being the price versus performance leader.


Legit Reviews Value Award

Legit Bottom Line: XFX obviously is very serious about getting a piece of the high performance power supply market pie, as the Pro Series 850W Black Edition is not “just another” high performance power supply. For $140.78 shipped after rebate, it is difficult to find another power supply offering such a balance in features, performance, aesthetics and price.