Corsair Professional HX850 850W Power Supply Review

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Corsair Professional HX850 850W Power Supply Review

Product Number: CMPSU-850HX
Price: Click Here to Compare Prices
Manufacturer’s Product Page: Corsair HX850W
TechWiki Info: Corsair HX850W
Warranty: 7 Years
Availability: Now



By now we all know that a quality power supply will not only help with system stability but it can also save you money on your electricity bill. As power supply reviews continue here at Hardware Canucks, it is becoming more and more evident that the powers that be are pushing efficiency above all else. The 80Plus designation has allowed manufacturers to give potential customers a tangible certification so they can better determine their power savings and many have embraced it.

While we hope that overall build quality will not be sacrificed to eke out the best possible efficiency numbers, some companies have made sure their old “high quality, high efficiency” mentality stays is place. As you may have already guessed, Corsair has been fighting with all hands on deck to ensure output quality remains top notch while efficiency numbers increase. One of their latest creations is the HX850; a power supply that promises to take this merry bunch of buccaneers to the pinnacle of power supply supremacy.

Even though this power supply is part of their new “Professional” series, many of you are probably thinking that the HX850 is nothing more than a modular TX850 that sports an accordingly inflated price point. Fortunately, there is much more lurking below the surface of this product and its sibling the HX750 than just a fancy paint job and a modular interface. These units use a completely different platform from anything that has been previously put in play by Corsair and the HX850 in particular is graced with an 80Plus Silver rating as a consequence.

There must be plenty of you who are saying “that sounds great, but what’s it cost?” Fortunately, a lot less than you may think. While many high quality competing 850W power supplies from the likes of Silverstone, Thermaltake and Cooler Master retail for above $200, the HX850 normally goes for about $210CAD and has been seen for $180CAD after mail in rebates are taken into account. With Corsair’s longstanding tradition of great customer support and one of the best warranties in the business at 7 years, customers have been shown to be more than willing to pay a slight price premium for their products.

This review will be particularly interesting since we will be comparing the HX850 directly to its less expensive, non-modular predecessor: the TX850. Will the newcomer have the performance necessary to make the price difference immaterial? We intend to find out.

 

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Specifications & Features

Specifications & Features

Output Specs

The HX850 has exactly what we want to see in power supplies of its calibre: a massive +12V rail. This is essential for powering today’s high powered systems which consist primarily of +12V hungry components like GPUs and CPUs.


Features

 

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What is the 80Plus Program and Does it Matter?

What is the 80Plus Program and Does it Matter?

The Corsair HX850 has an 80Plus Silver rating.

If you have been out of the power supply scene for the last year, you would be forgiven for not knowing what 80 Plus refers to or how it can affect your buying decisions when it comes to power supplies. The official designation has only been around in the industry since 2007 as part of the Energy Star initiative but it has since become extremely popular.

Before we go on, let’s give a quick, simple rundown about efficiency and what it means to you.

Efficiency numbers are based on the power loss that occurs when a power supply transforms the AC input power it draws from your household outlet into DC power. This DC power (12V, 3.3V etc.) is used by your components but the transformation process naturally causes some power loss. Higher quality power supply components will decrease this loss but only to a certain extent.

To put this into simple terms, a power supply which looses 30% of the input power through conversion has an efficiency of 70% and a power supply that looses only 15% has an efficiency of 85%. If we refine this down to the actual wattage consumption, if a system demands 600W of a power supply that has an efficiency of 80%, it will draw 720W from the mains. Indeed, you can begin to see how a mere 10% bump in efficiency can have a huge impact on the overall consumption of your system as well as your electricity bills.

In its most basic guise, the 80 Plus program provides manufacturers a way of certifying their power supplies for use above 80% efficiency. However, it isn’t the last word in efficiency measuring since manufacturers aren’t required to submit their power supplies to 80 Plus for certification. As such, there are plenty of power supplies on the market that exhibit amazing efficiency numbers but are not 80 Plus certified. It should also be noted that the 80 Plus certification does not guarantee you a quality power supply since it is possible that a highly efficient power supply could fall flat in other areas.

There are three certifications which are handed out by the 80 Plus organization for desktop power supplies. All of these certifications refer to the efficiency achieved by the power supply at 20%, 50% and 100% of its rated load.

At least 80% efficiency @ all stated loads & a PFC of .90 at 100% load

At least 82% @ 20% and 100% loads, at least 85% @ 50% load & a PFC of .90 at 50% load

At least 85% @ 20% and 100% loads, at least 88% @ 50% load & a PFC of .90 at 50% load

At least 87% @ 20% and 100% loads, at least 90% @ 50% load & a PFC of .90 at 50% load​

So what does the 80 Plus designation really mean to you? More and more consumers these days are looking for ways to save money while being environmentally conscious and normally this is a tall order of business. The 80 Plus certification allows people to quickly glance at the specifications of a power supply to easily determine what kind of pre-tested efficiency values that particular unit has. In this way they can know which products will be healthier for their electricity bill and the environment.

Without a doubt, this certification provides a great quick-reference point for the masses but as we already stated, it is not a requirement for manufacturers to have their PSU 80 Plus certified. This means that there are plenty of efficient units out there without the little 80 Plus sticker so make sure you do your research before making a decision on which power supply is right for you.

 

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Packaging and Accessories

Packaging and Accessories

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The box the HX850 comes in is a mirror image of other Corsair designs other than its use of the odd off-blue accent color. On the other hand, the back gives us a little more information than we were expecting. Along with the usual list of features, we are treated to some internal shots as well as an overhead cable picture.

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As usual, Corsair proves to be the master of efficient, well-rounded packaging. The power supply is extremely well protected by an exterior foam casing as well as a soft material wrapping while the modular connectors are pushed to the side in their own dedicated bag.

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When it comes to accessories, Corsair never skimps and this high-end power supply’s selection proves no different. Included is a multi lingual instruction manual, the aforementioned bag for the modular cables, black zip ties, a case badge and black mounting screws. The power cord warrants special mention since it is the same industrial-rated unit we have seen on numerous 1000W and higher power supplies.

 

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Exterior Impressions

Exterior Impressions

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Other than being predominantly black save for a few off-blue highlights, the first thing you will probably notice about the HX850W is that it is slightly longer than most other 850W power supplies. Being slightly larger than the ATX standard, it doesn’t quite match the length of its big brother the HX1000. The finish is also what we have come to expect with a durable powder coat that resists both scratches and fingerprints.

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The 140mm fan may dominate the upper side of the HX850 but in our experience; the bigger the fan, the less noise it produces.

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Other than the color used for the labels, there really isn’t much to distinguish the HX850W from the rest of Corsair’s lineup. The rear of the unit holds the usual on/off switch, a power receptacle and a perforated metal exhaust grille.

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The modular interface is simple yet effective and eliminates the possibility that you will plug a cable into the wrong connector. Basically, all of the standard peripheral cables are attached to the black 6-pin connectors while the blue ones are dedicated for the PCI-E cables.

 

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Cables and Connectors

Cables and Connectors

Click on image to enlarge​

Corsair power supplies are known for their generous number of connectors and more than adequate length cables. The HX850 is no different but there is at least one oddity: the lengths of the non-modular PCI-E 6+2 pin connectors. According to Corsair, the choice to go with a 19.5” length for these is based on feedback from their customers who wanted slightly shorter PCI-E cables so they wouldn’t have excess cabling to hide. The graphics cards are usually positioned near the center line of any case so the PCI-E cables would have less space to bridge versus say the CPU connector in an enclosure with a bottom mounted PSU. We tend to agree with this reasoning but would still rather see slightly longer cables. Luckily, the modular PCI-E cables are more than long enough for any situation.

Other than the shorter PCI-E cables, the HX850 has everything we would expect cable-wise from a high end power supply.

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Unlike some power supplies on the market, the HX850 uses a combination of modular and non-modular cables. While the cables fixed in place on the power supply itself are of the standard sleeved variety, the modular cables use standard wiring but are then flattened out and finished in a black plasticised material. This makes them easier to route through your enclosure and supposedly (though there is no evidence to support this) impede airflow less than standard cables.

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Up to this point, the Corsair HX850 had been displaying near-flawless attributes but when it comes to the modular PCI-E cables it unfortunately falls flat on its face. Flat cables are fine and dandy but when you need two of them per PCI-E cable, for crying out loud; just go back to using regular sleeved cables. The result is a cable that’s simply ugly, looks cheap and if you want a clean install you’ll actually have to zip-tie this cable to…itself. It’s pathetic really and an unacceptable addition on an otherwise amazing cable layout.

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Connecting the modular cables to the unit couldn’t be easier. They have a simple clip system holding them in place and as mentioned before, the PCI-E cables are color coded blue so you won’t mistakenly insert one of them into the wrong slot.

 

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Interior Impressions

Interior Impressions

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Popping the hood on this power supply reveals that it is indeed made by Channel Well Technology (CWT) much like Corsair’s TX-series. However, unlike the TX-series the HX850 is based off of a brand new platform called the DSG which is bred for high-efficiency output.

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Starting with the input filter, we can see that it is well-appointed and the soldering is overall quite well done. Meanwhile, at the front of the power supply it is good to see that the fragile sleeving on the cables has been protected from scratching by a rubberized ring around the sharp edges of this PSU’s enclosure.

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The primary side consists of a pair of Nippon Chemi-Con 105*C rated capacitors along with a transformer and the usual wrapped-coil design typical of Channel Well-based units. Something that really surprised us was the fact that the heatsinks within the HX850 are so small even though high spec’d rectifiers and diode packs are used. However, considering the efficiency numbers this PSU supposedly has, less heat will be generated meaning smaller heatsinks can be used.

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The secondary side consists of yet more Nippon Chemi-Con capacitors along with a few solid caps here and there for some added performance. Those two small vertical PCBs you see seem to contain the +5V and +3.3V circuitry and have their own dedicated copper plates to disperse the heat they generate.

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The thermal diode which is linked to the fan controller is attached to one of the primary heatsinks.

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Moving on to the modular interface we are greeted with a darn-near perfect soldering job for all the traces. This really is a textbook job here and just serves to put the icing on an already impressive interior design.

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The fan used on this power supply is the same as other 140mm-equipped Corsair power supplies: a 140mm Yate Loon unit with a ball bear fan which is rated to operate at a very high 2800RPM. Corsair has also seen the need to attach a clear plastic fan shroud to it in order to direct airflow to the most necessary areas.

 

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Testing Methodology

Testing Methodology

Sub-700W PSU test system has not yet been determined.

Test System Setup

Processor: Intel Core i7 920(ES) @ 4.0Ghz
Memory: Corsair 3x2GB Dominator DDR3 1600Mhz
Motherboard: Gigabyte EX58-UD5
Graphics Card(s): HD4870X2 Single and Crossfire (@stock speeds)
Cooling: CoolIT Boreas mTEC + Scythe Fan Controller
Disk Drive: Pioneer DVD Writer
Hard Drive: Western Digital Caviar Black 640GB
Additional Fans: 2x Yate Loon 1200RPM
Monitor: Samsung 305T 30” widescreen LCD
OS: Windows Vista Ultimate x64 SP1
* Open test bench


General Notes

*Each test is run over the course of 30 minutes.

*Please note that the Crossfire setup is only used for 900W and higher PSUs

*Unless otherwise noted, the Boreas TEC runs at a constant 100%


Idle Conditions

Off: Is a load value where the system is turned off but a small amount of power is still required.

Idle: Idle values are determined by a stable Windows Vista x64 desktop.

Idle + TEC: Reflects an idle conditions mentioned above but with the Boreas TEC’s running at 100% load

Idle + CF: Same idle conditions as indicated above with a pair of HD 4870X2 cards installed.


Load Conditions

CPU Load: This test is run with 8 instances of a custom Prime95 test which we have found uses the most non-GPU power. The test is run for 30 minutes.

GPU Load: For this test we are aiming to show power consumption in a typical fast-paced gaming scenario. As such, we load a single HD4870X2 with custom timedemo of Far Cry 2 at 2560 x 1600 with 4x AA enabled and set it to loop for approximately 30 minutes.

Max Load: For this test we use the single GPU setup running 3DMark06 Batch Render Test at 2560x1600 4xAA / 16xAF while running our custom Prime95 test on the CPU in the background. Once again, this is a 30 minute test.

Extreme Load Test: This is the big one which separates the boys from the men. Basically, it is the same test as the Max Load test but we add another HD4870X2 into the mix and tested for 30 minutes.


Voltage Regulation Testing Methodology

Multimeters Used:
Extech 430 DMM x3

*Note: All voltage readings indicated in the review are the minimum voltages seen over the period of our tests

We always take voltage readings from a loaded connector in order to more accurately see the voltage fluctuations our components are experiencing. Thus, this is how voltages are measured:

+12V: In the CPU Load test the voltages are taken directly from the CPU connector and the used 8-pin PCI-E connector of the power supply. In the GPU Load test the voltages are taken from an 8-pin PCI-E connector which is plugged in to the topmost graphics card as well as the CPU connector. In the Extreme Load test, readings are taken from both the CPU and the PCI-E connectors and the lowest reading is recorded.

+3.3V / +5V: From the main ATX connector.

Please note: Due to the lack of load on the +3.3V and +5V rails in a modern PC, we WILL NOT be including charts for their results unless there are noteworthy fluctuations.


AC Ripple Testing Methodology

Tolerances:

+12V : 120mV Max
+3.3V: 50mV Max
+5V: 50mV Max

The values were the highest peak ripple measurement across all of the +12V rails. So, if the +12V1 rail shows a ripple of 20mV and the +12V2 rail shows a ripple of 40mV, the highest value will be graphed.

Instruments Used:
USB Instruments Stingray Digital Oscilloscope
USB Instruments Differential Oscilloscope Probe

Since we do not have a load tester with a BNC connector for the standard o-scope probe, we needed a Differential probe in order to give us the proper capacitance to accurately determine ripple. In addition, the differential probe has a pair of connectors which are very much akin to a multimeter's probes which makes them ideal for use on SMPS designs. The locations of the probes for each test reflect the locations of the multimeter probes detailed in the Voltage Regulation Testing Methodology section.


Efficiency Testing Methodology


Instruments Used:
UPM Power Meter
Tripp Lite LC1800 Line Conditioner

The data points you see in our charts show the AVERAGE PEAK AC power consumption over all of the tests conducted.


Temperature Testing

Considering the amount of heat our open-air test system produces, it was found to be nigh-on impossible to properly regulate the temperature in the room even with a 10,000 BTU air conditioner. As such, we will be measuring the delta between room temperature and the exhaust temperature from the power supply.

To test temperature, we set up a pair of Type-K temperature probes. One is placed in the middle of the testing room at an elevation of 5 feet AFF to measure ambient temperatures. Meanwhile, the other temperature probe is placed 4” away from the exhaust grille of the power supply.


A few other tidbits

- AC Input Voltage: 120V constant
- Noise is subjectively tested

 

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Efficiency Testing

Efficiency Testing

Idle Efficiency

Load Efficiency

From our tests it seems like the Corsair HX850 is more than able to live up to its 80Plus Silver rating as it keeps pace with some of the best power supplies on the market. Indeed, even though its output wattage is identical to that of the TX850, the HX850 is able to trample the older unit when it comes to efficiency. If this Corsair power supply can continue this trend into the rest of the tests, we may have one hell of a product on our hands here.

 

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Voltage Regulation

Voltage Regulation

+12V Regulation (CPU Connector)

+12V Regulation (PCI-E 8-pin Connector)

Even though we haven’t reviewed many power supplies with this new test system of ours, we can safely say that the HX850’s results will surely stay among the cream of the crop for a long time. It simply has some of the best voltage regulation we have ever seen from a power supply. There really isn’t much else to say, is there?


+3.3V / +5V Regulation Notes

As our system does not draw much power from the +3.3V or +5V rails, the Corsair HX850 displayed next to no voltage fluctuations on either of these two rails. The maximum variance we saw was +/- 0.03V for each.