Corsair TX850M 80 Plus Gold Power Supply Review

Introduction Corsair TX850M As one of the most popular technology brands in the world, Corsair has a big reputation to live up to. Their PSUs are easily some of the best-selling in the world, loved by system builders and enthusiasts. With that in mind, we've got pretty high expectations of their new Corsair TX850M. Furthermore, previous reviews of Corsair PSUs have proven them to be some of the best on the market, and we wouldn't expect the TXM to be any different. Gold-certified efficiency and semi-modular cabling for low energy use and easy installation "TX Series semi-modular power supplies are ideal for basic desktop systems where low energy use, low noise, and simple installation are essential. All of the capacitors are 105°C rated, Japanese brand, to ensure solid power delivery and long-term reliability. 80 PLUS Gold efficiency reduces operating cost and excess heat. Flat, sleeved black modular cables with clearly-marked connectors make installation fast and straightforward, with good-looking results." 80 PLUS Gold-certified Efficiency "The super-efficient operation of the TX Series semi-modular results in lower energy use and lower operating costs. Since it generates less heat, the fan doesn’t need to work as hard, and you’ll enjoy near silent operation." Modular cabling with clearly marked connectors "The flat, sleeved black cables are semi-modular, so you’ll only use the cables you need and you’ll get great-looking results. The clearly marked connectors make installation fast and straightforward." Corsair Engineering and Quality Control "Every CORSAIR power supply is designed by our California engineering team and built to our exact specifications. The same care that goes into the design and testing of our renowned high-power enthusiast power supplies also goes into the TX-M Series semi-modular, because you need confidence and reliability regardless of your build budget." Features and Specifications With a semi-modular design, cable routing should be a breeze with the TXM series power supplies. Add to that 80 Plus Gold efficiency, sleeved cables, a high-quality 140mm fan, and a powerful 12V rail, and you've got all the boxes ticked for any high-end system build. Packaging & Accessories The box comes in the usual Corsair colours and shows off a clear image of the product on the front. On the top edge of the box, there is a detailed picture of all the included cables. The fun (and boring) technical details are dotted on the back, letting you know how the fan and efficiency levels perform at various load settings. Of course, we'll be testing those ourselves today too. Cables In the box, you'll find a good range of Molex and SATA cables for all your peripheral devices. There's also a pair of dual 6+2-pin PCIe cables. The motherboard 8-pin and the 24-pin are hardwired to the PSU, as every system will need those anyway. A Closer Look When it comes to aesthetics the TX850M isn't going to light the world on fire. It's a pretty standard looking unit and anyone who's used the mid-range Corsair units like this in the past will find it pretty familiar. That's not to say it looks bad though, it's a nice enough looking unit, but it lacks much in the way of thrills. To make the install process nice and easy the motherboard cables are hard-wired. They're made with all-black connectors and thick braiding on the 24-pin. Overall, the cables should blend into your build easily enough. There are six modular connectors on the back. The connectors include 2 x PCIe and 4 x peripheral; more than enough for most systems. Tucked into the top, you'll find a 140mm Corsair fan. The fan is very nice quality and is almost the size of the entire unit. The actual PSU is relatively compact, and the use of such a massive fan should allow it to run at low RPM even under heavy load. On the base, you'll find the specification sticker, nothing too complicated here. With lots of ventilation around the back, the TX should have an easy time keeping cool and providing good airflow. When you need to power down your system fully, there's a master switch on the back too. Overall, a relatively straight forward unit. Of course, a good quality fan and a durable chassis are no bad things, and the semi-modular cables are a welcome bonus too. So how does it perform? Important - Please Read To understand the results on the new few pages, please take the time to read our detailed testing methodology page. The next page of this review will help you understand what the results of our testing mean, and educate you on the various qualities we look for in a good PSU. Test Procedure At eTeknix we take the power supply testing procedure very seriously and have invested a lot of resources into acquiring the appropriate testing equipment. For all power supply reviews, we test the power supplies with dedicated power supply testing equipment. This means we are able to get the most accurate results from our testing as opposed to using software benchmarks (such as OCCT) or multi-meter readouts which are broadly inaccurate. Testing Hardware Sunmoon SM-5500ATE Active Load Tester (1200W rated) Stingray DS1M12 USB Oscilloscope Voltcraft DT-10L laser tachometer What the eTeknix Test Procedure Involves Testing each power supply at 20/40/60/80/100% load (with load balanced across all rails) and measuring PFC (power factor correction), efficiency (actual power divided by power "pulled at the wall") and voltage regulation (deviance from expected voltages of 3.3/5/12 on the main rails). Measuring ripple with an oscilloscope at 20/40/60/80/100% load. Measuring fan speed after a stabilisation period of five minutes at each load scenario using the Voltcraft DT-10L laser tachometer and a reflective strip on the fan. Testing each power supply's OPP (Over Power Protection) mechanism and seeing how many watts each power supply can deliver before shutting down Other Things to Consider We recognise that a single 12-volt cable can provide only 6 Amps before overheating (which corrupts voltage regulation and efficiency) and so we used an adequate number of cables for each power supply to ensure there is not efficiency loss from poor cables selection Our Sunmoon SM-5500ATE power supply tester is not capable of testing more than 300W on each of the 12-volt rails so where a power supply provides more than 300W on a 12-volt rail that power is distributed over multiple 12-volt rails on the load tester. For example a power supply with one 12 volt rail supplying 750 watts would be spread equally over three 12 volt rails on the load tester, a power supply with two 450W 12v rails would be spread over four 12v rails on the load tester, two 225W 12v rails for each of the 12v rails on the unit. We use the same time scale and horizontal millivolt scale on our oscilloscope for all ripple tests, that is a 20ms T/DIV (horizontal) and a 0.02 V/DIV (vertical) meaning the scale is from -80mV to +80mV, ATX spec dictates that the 12v rail must fall within 150mv of ripple and the 3.3/5 within 50mv so that scale allows us to include both 150 and 50mV peaks. (Some older PSU reviews use different scales which were later ditched as the visual representation they give is inadequate, in these reviews written measurements are provided only). Deviance is the terminology used to represent the way voltages diverge from the expected values Voltage Regulation To test voltage regulation we load the power supply to five different load scenarios that give an equal spread of load across every single rail. So that means 20% on all rails, 40% on all rails and so on. We then calculate the average deviance of each rail from its expected voltage. Ideally, anything of +/- 2% regulation is seen as a very good result. Power Efficiency Power efficiency is measured by calculating actual supplied wattage divided by the wattage drawn at the wall/plug, multiplied by 100 to give a percentage. We then compare that to the particular 80 Plus certification the company claims to see if it meets that. You can see the 80 Plus certifications below, we always test power supplies at 230v. Power Factor Correction Power Factor Correction is the ratio of the real power flowing to the load, to the apparent power in the circuit. The aim of PFC is to make the load circuitry that is power factor corrected appear purely resistive (apparent power equal to real power). In this case, the voltage and current are in phase and the reactive power consumption is zero. The closer the number to one the better as this allows the most efficient delivery of electrical power (Source - Wikipedia). Ripple Noise and Ripple can easily be measured by an oscilloscope. These show how much voltage fluctuation there is on a particular rail. We tested the rail stability of the 3.3 volt, 5 volt and 12 volt rails using an identical time and millivolt scale for all graphs. millivolt ripple is measured by the peak to peak size of the voltage curve. The latest ATX 12 volt version 2.3 specifications state that ripple from peak to peak must be no higher than 50 millivolts for the 3.3 volt and 5 volt rails, while the 12 volt rail is allowed up to 120 millivolts peak to peak to stay within specifications. Millivolt figures are stated to the closest increment of 5 given their variability. OPP Power supplies often quote as having various protection mechanisms such and the most important of these is Over Power Protection. In our testing we crank up the power draw until the power supply either shuts down (meaning the OPP mechanism is present and working) or blows up (meaning it is either not present or not working). We then note the maximum power consumption before the power supply shut down, or before it blew up. Fan Speed When testing in a power supply laboratory it is difficult to take fan noise readings as the noise from the Sunmoon test equipment and air conditioning corrupts everything. The next best thing in our circumstances was reading off the fan speed with a tachometer to get an idea for the noise. The ambient temperature during testing held constant at 22 degrees, with 1 degree of variation. Each power supply had a consistent time period of 5 minutes to stabilise between each load scenario. In my experience the following general relationships apply between noise levels and fan speeds, though it can vary greatly between the type of fan used. Below 800 RPM - Inaudible/Silent 800 to 1000 RPM - Barely audible 1000 - 1200 RPM - Audible but still quiet 1200 - 1400 RPM - Moderately noisy 1400 - 1800 RPM - Noisy 1800 RPM or above - Intolerable Efficiency, PFC and Voltage Regulation Voltage Regulation This power supply promises to deliver very tight voltage regulation, and I'm happy to report that holds true. The tolerances are superb, with the exception of the -12v, but that's still in the green zone, and far from a problem. The ones that really matter are the 12V, 3V and 5v, and they're looking great. Power Efficiency Rated at 80 Plus Gold, this unit is certainly efficient. However, it's of 91/93/91% puts it very close to the 90/94/91 required for Platinum efficiency, making it exceptional value for money overall. Some units barely make Gold rating; this one maxes it out. Power Factor Correction The PFC is superb on this unit, hovering between 0.94 and 0.975. It's also at its best in the most common scenarios of low and high load, which is always good to see. Ripple Corsair power supplies are well known for their low-ripple power delivery. This one isn't as good as their higher end units, but that's hardly a shock. The 12V rail is a little noisy for a Corsair unit, but still well within the recommended maximum of 150mv. The 3.3 and 5V rails on the other hand feature very low ripple. Overall, this is great and you can expect pretty consistent and clean power delivery from the PSU. Load (%) 3.3V Ripple 5V Ripple 12V Ripple 20 4 3 16.6 40 5 3.6 19.8 60 6.4 4.2 26.4 80 7.4 5 35 100 9.2 6 45 3.3 volt @ 100% 5 volt @ 100% 12 volt @ 100% Over Power Protection and Max Wattage Recently, I've noticed a lot of PSUs in this class benching well above their weight, and the latest from Corsair is no exception. Typically, I would expect a PSU of this calibre to pull around 950W at the most before shutting down. The Corsair unit peaked at 1102 before the OPP kicked in, which is pretty nuts, to say the least. Power spikes while gaming? They're not going to slow this unit down. Fan Speed This looks a little crazy, but look closer, as the fan only changed from around 730 to 815 RPM in all our tests. That's incredibly slow for a PSU fan and shows why Corsair fitted it with a 140mm model. That fan at this RPM is virtually silent, so we doubt you'll ever hear it whirring away. Final Thoughts Pricing The Corsair TX850M 80 Plus Gold Semi Modular Power Supply is currently priced at £123.95. That's an interesting price, as it does put it in line with some rival hardware that costs about the same. Some other units for the same price offer fully modular cables, some even offer a longer warranty. However, for an 80 Plus Gold unit, with a 7-year warranty, it's not like you're missing out. Some units may be fully modular, but unless you're custom braiding call cables, does it really matter that two cables are hard-wired? Not really. Conclusion With such a strong reputation in the system building market already, we know for sure that the TX850M is a sure-fire hit for Corsair. It's priced about right, it delivers massive amounts of power and ticks all the right performance boxes. Personally, I think the brand name alone is enough for this PSU to sell well. Of course, those interested in the more technical aspects will find enough to appreciated. Huge Amounts of Power The OPP performance was amazing, pulling well over a 1000W on an 850W unit is no bad thing. While I wouldn't suggest running it over its rating for extended periods, it's fine for a bit of extreme benchmarking and it'll eat up those power spikes. However, should your system suddenly draw 1500W (unlikely), at least we know the OPP will kick in and shut the PSU off before something explodes; now that's good peace of mind! Good Efficiency is Like Money in Your Pocket At the upper end of the 80 Plus Gold specification, and even stepping into the 80 Plus Platinum spec, the TXM is very efficient. That means when you take in power from the mains, it's not wasting much power, and that can mean a nice saving on your electricity bill. While it's not going to save you a fortune, keeping those bills down and being a green as possible is never a bad thing. Ripple, Volts, and All Things Nice With perfectly stable and consistent voltages on all rails, those seeking good overclocks will be happy to see the robust performance from the TXM. The ripple is nice and low too, sure the 12V rail is a little noisy compared to some other Corsair units, but it's still more than good enough for the job. Pros Durable build quality Stable voltages Low ripple (3.3v/5v) Fantastic OPP performance Low RPM 140mm fan Superb efficiency Semi-modular cables 7 Year Warranty Cons None Neutral 12v rail ripple could be improved but is far from a deal breaker Design is a bit bland "The market is very competitive, but the TX850M can certainly hold its own. Delivering impressive power output and stability, with fantastic efficiency to match. It's sure to be a compliment to any system build."