XFX Black Edition 850w ATX PSU Page: 1
XFX LogoTHIS image is something most of us will have undoubtedly seen floating around the net for quite some time now. It caused quite a stir over on our forums, and undoubtedly other enthusiast forums all around the globe too. First shown off at Computex earlier this year and only fully confirmed for release a short while ago, XFX's first foray into the PSU market was obviously never going to be a quiet one.
However, GPU manufacturers entering the PSU market is by no means a new thing. Back in June I had the opportunity of  reviewing a 1200w unit from BFG which failed to impress due to poor performance and quality control issues. Furthermore, Sapphire Technology also recently announced their own PSU range which we already have their 1250w model in the labs for testing. Add to this the already well established list of PSU manufacturers such as OCZ, Corsair, Enermax, Be-Quiet..etc..etc..etc and any manufacturer wanting to muscle in on the power supply market is going to have a hard time finding their feet unless they've got something quite special.

XFX of course have pulled out the big guns and launched their first PSU as part of the "Black Edition" range which traditionally only encompassed their high-end pre-overclocked graphics cards. The 850w unit sports a green and black attire that will of course look right at home inside any PC kitted out with an XFX nVidia GPU or Motherboard, but let's start by checking out the specs to see if XFX have done their homework:
XFX 850W Black Edition Modular PSU (P1-850B-NLG9)
Designed specifically for the high performance gamer, the 850W Black Edition PSU supports multiple high-end graphics cards. Offering an array of unparalleled features, the 850W PSU delivers exceptional performance:

• Specifically designd to support multiple, high-end graphic adapters
• Single, high-power +12V rail eliminates the problems associated with multiple +12V power distribution
• Industrial grade components insure high reliability and long life
• High efficiency not only helps protect the environment but also allows the XFX 850W PSU to run cool and quiet
• Combining both fixed and modular cables delivers superior performance and flexibility

• 850W of continuous power at 50°C
• Tight voltage regulation (±3%)
• High efficiency operation up to 90% (80 Plus Silver)
• Single, high power +12V rail (up to 70A/840W)
• DC to DC voltage Regulator modules for +3.3V and +5V
• High quality Japanese brand capacitors (105°C)
• Solid polymer caps provide enhanced reliability and stability
• Quiet 135mm ball bearing fan provides superior cooling
• Supports multiple high-end graphic adapters (NVIDIA SLI and ATI CrossFire Ready)
• Supports the latest ATX12V and EPS12V standards
• Active PFC with Universal AC input
• Detachable modular cables
• Energy Star 4.0 and RoHS compliant
• 5-Year Limited Warranty, subject to registration
The Black Edition 850w boasts up to 90% efficiency with an 80PLUS Silver rating, a single 12v rail, Japanese 105°C capacitors, +3.3v/+5v DC-DC modules with solid state caps and a 135mm fan. Naturally support for multiple high-end graphics cards is also on the list, but we're not going to find out exactly how many PCI-E connectors are included until we take a closer look over the next few pages.
XFX have also included a 5yr warranty which should go down well with those of us who keep their hardware for longer than a few months before upgrading. However, do note that you need to register the product in order to take advantage of this, otherwise you'll be stuck with a fairly basic 1yr warranty and a dent in your forehead from the repeated *facepalm* should the PSU go belly up after this time.
XFX Black Edition 850w Rail Layout
DC Output +3.3V +5V +12V1 +12V2 +12V3 +12V4 +12V5 +12V6 -12V +5VSB
24A 30A 70A - - - - - 0.8A 3A
Max Power 150W 840W 9.6W 15W
Power output is fairly common for an enthusiast orientated PSU with almost all of the 850W output being available on a single 12v rail should it be required. As XFX have already said, this eliminates any potential issue where a high current +12v device (such as a graphics card) could trip the OCP (Over Current Protection) on a PSU with say 6 rails rated at 20A each. Some urban myth surrounds this idea though, as most PSU's with 'multiple rails' tend to have each of the PCI-E connectors attached to different rails thereby avoiding this issue entirely.
Anyway, it's fair to say from the specs list at least that XFX have put together a PSU that should have most enthusiasts putting their hands in their pockets reaching for their..ahem...wallets right now. So let's press on with the rest of the review to see if it lives up to our expectations.

XFX Black Edition 850w ATX PSU Page: 2
Packaging & Appearance
Starting off with the graphical design of the packaging, the word 'striking' really does not do any justice. XFX have combined a dark 'DOOM-like' grey and black mechanical design along with bright retina burning dayglow green highlights. Aside from the large "850" text and SLI/80PLUS certification stickers there really is very little information on the front of the box, but with a design like this it is highly unlikely that any enthusiast or gamer could casually walk on by without feeling the urge to pick the box up and find out exactly what is inside.

XFX 850w Front XFX 850w Side
XFX 850w Back XFX 850w Box Side
The bulk of the information has been placed on both the back and sides of the box, with the feature list and rail distribution charts seen back on the previous page making a reappearance. A glossy picture of the PSU is also printed at the back of the box, but to be honest I think that XFX have missed a trick by not incorporating some kind of window into the packaging so that potential buyers can get a good look at the actual unit contained within.
XFX 850w Packaging XFX 850w Modular Cable Box
XFX 850w Box Open XFX 850w Box Contents
Sliding off the outer cardboard layer reveals a two-tiered box design with the top box (modular cables) interlocking into the bottom box (PSU) with some rather simple cardboard tabs. Opening the larger of the two boxes gives you your first glimpse of the actual PSU with XFX keen to show off the spider web style fan grill and fluorescent green 135mm fan through the middle of two black cardboard flaps. Yet another smaller box can also be found beneath one of the flaps, which is beginning to make me think that XFX borrowed their packaging design from a matryoshka doll!
Slightly disappointing is that XFX haven't placed the PSU inside any kind of protective bag, instead leaving it to ride bareback against the cardboard. Hopefully this shouldn't be a problem as the paint on the PSU feels quite hard wearing, but never less there's nothing worse than having your latest purchase arrive at your door in anything less than pristine condition, so maybe the lack of protection could be addressed.
Included in the box is a fairly basic set of accessories. Your get both a UK and Euro mains cable, a set of case screws and a rather snazzy canvas pouch full of modular cables. Some velcro cable ties would have been nice, but I'm not going to moan.
w0000t thats 2 down, just one left! XFX 850w Rear
XFX 850w Side XFX 850w PSU Side
Moving on to the appearance now and you'd be forgiven for thinking that the unit had fallen off the back of a UFO. XFX really have gone all-out to make this PSU look as extraordinary as possible while still obviously retaining the standard ATX form factor. The aforementioned spider-web style fan grill is obviously the most striking of changes and coupled with the green fan blades, goes a very long way to separating it from the rest of the crowd. A cog-like pattern has also been punched into the top casing of the unit, which joins with three 'valleys' that run down the modular connector area.
The rear of the unit is fairly standard with a square exhaust grill dominating most of the available space. Given the look of the rest of the unit I was half hoping that XFX may have at least installed a couple of green status LED's just for 'extra effect' but alas the only customisation in this area is the vertically mounted XFX logo sticker.
  XFX 850w Modular Area XFX 850w Modular Area
Around the front of the unit are a total of eight PCI-E style modular connectors all finished in lime green plastic. Although this looks immensely good, it is slightly worrying to think that someone may try to force one of the 6-Pin connectors used for the SATA/Molex cables into one of the 8-Pin graphics card connectors thus delivering +12v down the +3.3v and +5v wires. Not that I'd want to spoil the style of the unit, but maybe some kind of visual aid would have been useful to help differentiate the two styles of connector.
Now let's move on to the next page and take a look at the cables and PSU internals in more detail...

XFX Black Edition 850w ATX PSU Page: 3
Cables & Connectors
As we've come to expect from most modular PSU's, the XFX Black Edition also has a limited number of hard-wired connectors that are essential to the operation of any normal PC system. This not only simplifies the modular connector interface at the front of the PSU, but also ensures that devices such as the motherboard and primary graphic card receive the cleanest power without any potential noise from a poor modular connection. 
XFX 850w Cable Bundle XFX 850w Hard wired
Full compatibility with both old and new motherboards is provided in the form of an ATX connector which can be changed between 20Pin and 24Pin standards by simply removing a 4Pin connector block. One of the two 8Pin EPS-12v connectors also shares a similar trait in that it can also be broken in half to reduce the connector down to 4 Pins, providing compatibility for the older P4-12v motherboard standards. Finally, the the hard-wired PCI-E connectors are also fully compatible with both 8Pin and 6Pin standards, avoiding any power issues with some graphics cards.
XFX 850w Modular Cables XFX 850w Modular Cables
Moving on to the modular cables, a total of nine are included in the bag with four being assigned to SATA, three as Molex and two as PCI-E. This essentially mean that with all available modular connectors on the PSU in use, one cable will be left over. Whether this ends up being an SATA or Molex cable is entirely down to the requirements of your system, but I'd certainly wager a bet that very few people out there are going to need more than one or two of the SATA cables plugged in anyway.
XFX 850w Modular Cables XFX 850w Modular Cables   
The sleeving on the cables is of decent quality with very little of the cables underneath showing through. However, I cant help but think how much better this unit could have been with some custom cables (possibly in green) to help continue the "not your average PSU" look that XFX have going. It almost seems like XFX lost interest half way through and decided to throw in whatever cables they could find in the parts bin.
The graph below shows exactly what connectors are provided with the PSU:
XFX Black Edition 850w Connectors
 ATX Connector Native 1x 20+4 Pin
 EPS-12v / P4-12v Connector(s) Native 1x 4+4 Pin / 1x 8 Pin
 Molex Connectors Modular 8x
 Floppy Disk Connectors Modular 2x
 SATA Connectors Modular 12x
 PCI-E Connectors Native / Modular 2x 6+2 Pin / 2x 6+2 Pin
Unfortunately there is no support for a high-end Tri-SLI setup due to a 'lack' of PCI-E connectors, but it certainly wouldn't surprise me if XFX have a 1KW version of the Black Edition with 6x PCI-E connectors ready to launch depending on the feedback they receive from the 850w model.  Everything else is pretty much as you'd expect from an 850w unit, and as we've covered already, even though there is a total of twelve SATA connectors on four cables and eight Molex connectors on three cables, not all of these can be plugged into the unit at once. 
Internal Components
Removing the lid of the XFX Black Edition 850W was essentially the same as any other PSU. Unscrew the four screws positioned on each corner of the unit and lift the lid off. However, as some of you may have already noticed in previous pictures, the Black Edition doesn't have any screws to hold the fan in place on the outside of the unit. This is because the fan actually has its own separate metal assembly that independently holds it in position above the PSU components. If XFX went for this design all in the name of vanity, then it is certainly an admirable effort.
XFX 850w Internals Fan XFX 850w Internals
With the fan out of the way you can get a good look inside the unit. At first glance everything appears to be quite well arranged with the capacitors and transformers in a row down the middle of the unit and all mosfets on either side attached to rather large silver aluminium heatsinks. Although I wouldn't like to put my money on it, the general layout does look extremely similar to something that would come from the Seasonic household. Anyone else agree?
XFX 850w Insides XFX 850w Insides
XFX 850w Capacitors XFX 850w Capacitors
The primary (high voltage) capacitors are manufactured by Japanese company Nippon Chemicon and carry the rating of 400v / 390uF / 105°C. This high quality is also carried over to the secondary (low voltage) side of the unit where a range of Nippon Chemicon KZE capacitors has been used, most with specs of 16v / 2200uf / 105°C. Even looking at some of the smaller capacitors, or caps hidden on the modular connector backplane, everything is Nippon. Hopefully this will translate to some really nice scope results and a long PSU life.
XFX 850w Transformers Seasonic in disguise XFX 850w Tranformers
XFX 850w Ferrite XFX 850w DC-DC
Potentially confirming my Seasonic OEM theory is the logo printed on the smaller (5vSB) transformer. This is without doubt the "S" Seasonic logo, and at the very least shows that they've had some hand in the build of the unit. The larger of the two transformers is unbranded, but as usual is responsible for the bulk of the 240v > 12v conversion which is then further converted into +3.3v and +5v by the DC-DC daughterboard pictured hiding below the heatsink in the picture above-right.
XFX 850w ADDA Fan XFX 850w Fan
The 135mm fan as you all know by now is green...very green. What you might not know is that this particular model is manufactured by ADDA Corporation with a model number of ADN512HB-A91. According to their website, this particular model carries a spec of 2200RPM / 95CFM at 39dbA. Not too bad providing it doesn't go full tilt when under heavy load.
Now on to the testing...

XFX Black Edition 850w ATX PSU Page: 4
Simulated Load Testing
To provide accurate and consistent results in all of our PSU testing, Overclock3D uses professional grade DC electronic load equipment capable of placing a sustained load of 3690w across a total of six rails (including +5vsb and -12v) on the PSU! This is achieved by using a combination of SunMoon and Analogic electronic load equipment which allow us to adjust amperage loads in increments as small as 0.01A while also measuring voltage and wattage readings on-screen.
During today's tests, we will be placing the XFX Black Edition under 25%, 50%, 75% and 100% load levels inside a hot box regulated to a temperature of around 50°C. Additional 'Cross Load' and a 'Max Load' tests will also be performed under these conditions to simulate how the PSU reacts to heavily uneven loads as well as running above its specified output.
XFX Black Edition 850w Results @ 50°C
   +3.3v  +5.0v  +12v  +5vSB  -12v  AC Watts /
 DC Watts
 Efficiency  Intake /
Δ Temp
Test 1
4.37A 4.37A 14.00A  0.75A  0.20A  242w /
 88.01% 50.4°C /
3.40v 5.12v 12.16v 5.00v  -12.05v
Test 2
8.75A 8.75A 28.00A 1.5A  0.40A  471w /
 90.23% 51.4°C /
12.10v 4.96v  -12.06v
Test 3
13.12A 13.12A 42.00A  2.25A  0.60A  705w /
 90.21%  49.5C /
3.38v 5.08v 12.06v 4.93v -12.11v
Test 4
17.50A 17.50A 56.00A 3.00A  0.80A 948w /
89.55%  51.0°C /
3.37v 5.07v 12.00v 4.89v -12.17v
Test 5
17.00A 16.00A 1.00A 0.00A 0.00A  182w /
82.96% 51.6°C /
-2.3 °C
3.39v 5.11v 12.14v 5.01v -12.60v
Test 6
 1.00A  1.00A  70.00A  0.00A 0.00A 939w /
90.52% 50.8°C /
3.40v 5.14v 12.02v 4.98v -14.33v
Test 7
 22.00A  22.00A 61.00A  4.00A  0.80A  ----w /
--.--%  --.--°C /
-.--v -.--v --.--v -.--v --.--v
XFX Black Edition 850w Performance Overview
 +3.3v Diff.
 +5.0v Diff.
 +12v Diff.
+5vSB Diff.
-12v Diff.
Avg Effic.
Noise Rating
0.88% 0.97% 1.31%  2.20%  0.99% 89.50% Low
Before we get to the big red part of the chart I first want to draw your attention to the standard tests 1-4. These best reproduce the kind of load that the PSU will receive when installed inside a PC. As we can see from the results and indeed the performance overview chart above, the XFX Black Edition 850w has some of the most stable rails I've ever seen in any PSU tested before on OC3D. The +3.3v and +5v rails are especially solid with less than a 1% drop in voltages from a low to full load which even bests our current favourite PSU, the Corsair HX850w. Efficiency was also extremely good with a high of 90.23% being seen at a 425w load in test 2 and an overall average of 89.50%.
However, all is not well. Part of OC3D's PSU testing procedure involves a "MAX Load" test in which the PSU is placed under a continually increasing load which takes it outside of its rated specification. This not only identifies the true capabilities of the PSU (for example if it is a 750w PSU overclocked to 850w, or a 1000w PSU underclocked to 850w) but also ensures that the OCP (Over Current Protection) is fully functional on the unit. Unfortunately this is where the XFX failed in a BIG way.
During this test the load was increased to 22A on both the +3.3v and +5v rails and 62A on the +12v rail. This combined with the small load on the +5vSB and -12v rail equated to around a 970w load on the PSU (120w above rated output). At first, everything appeared to be working fine. The ripple results were perfectly acceptable, the exhaust temperature was around 65°C and the voltages were all well within spec. Around a minute later the PSU powered off. Nothing unusual there, OCP had kicked in and saved the day. To find out whether the unit would be capable of sustaining a slightly lower load, the +12v rail load was reduced to 61A and the PSU powered back on. What happened next warranted a change of underwear...

An EXTREMELY loud BANG (heard even two floors down!) was emitted from the PSU accompanied by a bright flash. Yes, the XFX Black Edition had failed in a potentially dangerous way. Luckily none of the OC3D equipment was damaged by the elaborate death of the XFX PSU, but it is extremely worrying that the OCP protection on the PSU didn't kick in for a second time. Of course this could be put down to the unit being from a faulty batch, but as the unit tested in the video was the 2nd one to suffer this exact fate at the hands of our MAX LOAD tests, something does indeed seem wrong.
XFX Black Edition 850w Scope Results @ 50c
   +3.3v  +5.0v  +12v
Test 1
T1_3.3V T1_5V T1_12V
Test 2
t2_3.3v t2_5v t2_12v
Test 3
t3_3.3v t3_5v t3_12v
Test 4
t4_3v t4_5v t4_12v
Test 5
t5_3.3v t5_5v t5_12v
Test 6
t6_3.3v t6_5v t6_12v
Test 7

Finally we come to the +3.3v, +5v and +12v ripple results as recorded using a Rigol 25Mhz 400MSa/s oscilloscope during the load tests further up the page. Once again, the standard test 1-4 are exceptional with the ripple hitting a high of 30.4mV on the +3.3v rail, 22.4mV on the +5v rail and 36mV on the +12v rail. Even the cross-load results come back all-clear with a maximum ripple of 60.8mV on the +12v rail during test 6. Of course, the big let-down is once again Test 7 where I didn't have a chance to record any results before the unit met its untimely demise.
Now let's move on to the conclusion where I try to sum up everything seen today...     

XFX Black Edition 850w ATX PSU Page: 5
XFX Black Edition 850wConclusion
If you can excuse the slightly distasteful pun, XFX have entered the PSU market with a bang! During the traditional load tests the unit performed excellently, managing between 88-90% efficiency with extremely tight voltage regulation that stayed below 1% fluctuation on the +3.3v and +5v rails, and only hit 1.31% fluctuation on the +12v rail. Simply excellent. Add to this the low output temperatures and silent operation and the XFX Black Edition has all the ingredients to be a worthy competitor of Corsairs HX850w unit.
Attention has also been paid to the appearance of the unit, with some highly unique styling that has transformed what could have been a standard oblong box into something you’d expect to see on the set of an alien sci-fi movie. The lime green accents such as the fan, modular connectors and logo stickers absolutely scream XFX, and when combined with a pair of similar styled Black Edition graphics cards will undoubtedly look the part. However, I can’t help but think that XFX could have been a little more creative with the modular cables, which have been treated to just the usual black sleeving affair. On the other hand this could be the saving grace for people who want to complete an XFX trilogy inside their PC without overdosing on citrus.
Right about now I’d probably be contemplating an award such as Editors Choice or maybe Gamers Choice and an almost full-bars score. But unfortunately as I’ve already covered on the previous page, the XFX Black Edition 850w does have a a tendency to go ‘pop’ under certain load conditions. These conditions were of course outside specification during the "Max Load" tests where the unit was placed under a load approaching 1000W, but under no circumstances should a PSU of this quality fail in this manner simply because the load is too high. OCP (Over Current Protection) should kick in every time, saving both the PSU from failure and your hardware from being 'zapped'. For this reason alone the Black Edition 850w won't be walking away with any awards today, which is a great shame considering how well it performed in all other areas.
Any feedback from XFX will of course be posted at the end of this review.
The Good
- Borderline 80PLUS Gold level efficiency.
- Silent operation at loads of up to 750-800w.
- Rock solid voltages across all rails in standard tests (1-4).
- Extreme appearance.
- Unique Packaging.
- Great ripple results.
- 5yr Warranty.
The Mediocre
- Efficiency drop to 82% in cross-load test 5.
- Out of spec -12v output in cross-load test 6.
The Bad
- OCP failed to power off unit in max-load test 7 before it died with a bang.
Discuss this review in our forums.