Antec HCG850 Pro Platinum ATX 3.1 Power Supply Review

The Antec High Current Gamer series is a bit of a legend in the world of PSUs. I've had HCG units that have lasted 10 years without issue, they've a reputation for being practically bullet proof in terms of reliability, and with the new HCG850 Pro Platinum ATX 3.1 power supply in the office today, I'm honestly expecting nothing short of excellence from this PSU today. With it certified for ATX 3.1, and PCIe 5.1 standards, and 80 Plus Platinum efficiency, it's obviously a reasonably high-end PSU. While I'm reviewing the 850W unit today, there's also a 1000W and a 1200W version should you need even more power. Equipped with 100% high-quality Japanese capacitors, PhaseWave™ Design with a "server-class" full-bridge LLC design, DC-to-DC topology, and a full suite of industrial-grade protections including OCP, OVP, UVP, SCP, OPP, OTP, SIP, and NLO, the HCG Pro is ticking every box we could hope for, so it should deliver some impressive efficiency, stability and low-noise power delivery in our testing. Having had a sneaky peak at these at Computex 2024, I'm eager to get started, so let's get to it! Antec HCG850 Pro Platinum ATX 3.1 and PCIe 5.1 certified 12VHPWR connector 105c Japanese Main Bulk Capacitor 125mm FDB Silence Fan with Zero RPM mode 80 Plus Platinum certified Fully modular design DC-to-DC LLC OCP, OVP, UVP, SCP, OPP, OTP, SIP, and NLO What Antec Had to Say "Presenting our High Current Gamer PRO Platinum ATX3.1 power supplies, designed with the ultimate quality and stability in mind for gamers and enthusiasts. With the ground-breaking features like ATX 3.1, PCIe 5.1, 100% high-quality JP capacitors, 80 PLUS® Platinum-certified efficiencies and other more, you can expect second-to-none performance from your system. The PhaseWave™ Design ensures steady power output, while the 135mm FDB Silence Fan offers quiet cooling. The power supply is also 100% Modular, allowing for easy cable management and customization. The Zero RPM Manager enables advanced thermal control, ensuring the optimal balance between silent operation and efficient cooling. The CircuitShield™ full suite of industrial-grade protections provides safe and reliable power delivery under any circumstances. HCG850 PRO Platinum ATX3.1 is the perfect choice for your cutting-edge PC system." Packaging & Accessories The box is simple enough, with a good photo of the power supply on the front, and all the main features and specifications are clearly presented, such as the wattage, efficiency, ATX 3.1, and PCIe 5.1 certifications. Around the back, there's a good amount of information for those who want to know more about the efficiency, fan curve and zero RPM modes, and of course, the available connectors and included cables. In the box, you'll find the PSU comes with a protective bag, albeit a fairly basic one, as well as the mains power cable. All of the cables are premium quality, with individually sleeved wires, and and dark grey on black design that's sure to look fantastic in any system. A Closer Look The Antec HG is a pretty robust looking power supply, with an appealing industrial-esque aesthetic that's sure to look great in a workstation, gaming PC or any other system build for that matter. There's lots of ventilation up on the top, with a larger 135mm FDB Silence fan that should deliver big airflow even at lower RPM. Down the side of the power supply, there's a large sticker with the branding, if anything, I think there's a little too much going on here, and would prefer something more understated, but then again, my PSU will likely end up under a PSU shroud where I can't see it, so it's a bit of a moot point. Of course, it's the same design on the other side. At the back, there's a rather unique design on the ventilation, and plenty of ventilation at that, so getting heat out the back on of the PSU should be easy enough. There's a hybrid mode switch too, allowing for zero RPM functions when the PSU is under a temperature threshold. Finally, onto the business end, we can see the connectors are split up into multiple sections to make it easier to see what's what. There's the motherboard at the top, the SATA/Molex at the bottom, PCIe/CPU on the right, and the +12VHPWR in the bottom corner. Not a vast number of connectors, but keep in mind this is only an 850W unit, and the bulk of that is going to go to the 12VHPWR. A Closer Look - Interior Antec has used a 135mm FDB Silent Fan on this power supply, it's a very good quality fan too, so while it does support a ZeroRPM mode for complete silence in low-loads, even when this fan is going faster, it should be impressively quiet. The interior of the PSU is very clean and tidy, which isn't that surprising given that it's 80 Plus Platinum rated, as more efficient units tend to be better designed and optimised to reach better efficiency standards. There are two main bulk capacitors, and just like every other capacitor in this PSU, they're all Japanese made high-quality units, which promise more durability, reliability and longer life span. Both are rated for 105c and 420v, one is 330uF the other 390uF. The HCG850 used Antec's PhaseWave Design, which they say is a "server-class full-bridge LLC design" and that's pretty common to see this approach on higher quality power supplies, using a DC-to-DC topology, which gives improved stability, but also much better efficiency and lower heat generation. Towards the back, there's a small daughter board where we can see the 3.3v and 5v coils. And the AC Line-in looks robust and well shielded. Overall, a very clean and robust looking power supply, not that I would have expected anything less from the iconic HCG series. Methodology & Testing 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 can 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-8800 Active Load Tester 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") which also uses a 50% load test, 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. Transient loads taken with an oscilloscope are taken from 0% to 100% on the 12v raid, 3.3v rail, and then both combined. Measuring fan speed after a stabilisation period of five minutes at each loading 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. Any deviation from this will be explained per review as appropriate on the respective testing pages, but this methodology page will remain unchanged. 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) so we used an adequate number of cables for each power supply to ensure there is no efficiency loss from poor cable selection. If there is more than one 12VHPWR on a PSU, all will be used to test their combined loads. 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 deviation 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 the 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. Transient Loads Power Factor Correction Power Factor Correction is the ratio of the real power flowing to the load, to the apparent power in the circuit. PFC aims 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 An oscilloscope can easily measure noise and Ripple. 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 are often quoted as having various protection mechanisms 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 of the noise. The ambient temperature during testing is held constant at 22 degrees, with 1 degree of variation. Each power supply had a consistent 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 - 2000 RPM or above - Intolerable Internal Components This is just an example of what you can expect to see on a PSU interior. Efficiency As expected, the efficiency is right on the money, scoring well about 90% throughout all the testing and well within the Platinum specification. PFC (Power Factor Correction) Even better is the PFC, which is extremely close to the perfect score of 1.0, meaning less power is wasted, less heat is generated, and shows the benefit of their DC-DC design. Voltage Regulation Voltage regulation is excellent on the 12v, 5v, and 5vsb rails. However, the 3.3v is running a bit under, but honestly, I'm seeing this more often than not these days, it seems to be common as most motherboards just draw from the 12v and convert. Ripple We aim to see under 50mv on the 12v rail, and yet this PSU is between 15 and 18mv which is certainly fantastic and well within the 50mv target we expect to see. However, it's under 150mv for the other rails and given their in single digits throughout, it's safe to say that ripple is extremely low on this PSU. 3.3V 5V 12V Over Power Protection and Max Wattage 850W is plenty of power for mid-to-high-end systems, but this PSU is seriously over built, and was able to draw over 1200W before the OPP kicked in, so dealing with power spikes certainly isn't going to be an issue. Cross-Loads Cross loads are very consistent, with our ideal target being with 3%, the 5v and 12v are obviously on point here, however, the 3v3v is out by 10%, but this was expected based on what we saw in the voltage stability tests. Fan Speed The fan is very quiet, even at higher speeds, it was no louder than a good quality case or cooler fan, and of course, in hybrid mode, the fan is completely silent until the PSU hit around 50-60% load. How Much Does it Cost? Unfortunately, I couldn't see stock for this one at the time of writing, but you can check for up to date stock and prices on Amazon here. However, similar products on the market are priced around £160-200, and with the premium quality cables on this unit, I'd expect it to be slightly on the higher-end of that scale, as Platinum rated units tend to be more expensive anyway. Overview Antec has a long history with their HCG series, and they were some of the best power supplies I ever tested back when I first started here at eTeknix. Many of those HCG units saw many years of heavy usage in my office and own systems too, and I can honestly say I never had a problem with them. I only replaced them as my power demands increased or I simply had the opportunity to get something new for a build. Thankfully, their reputation for reliability is still strong, with great quality components used throughout, delivering strong power delivery that far exceeded the 850 watts, meaning you can draw big power when you need to without cause for concern. These power supplies are rated for "continuous power" too, so it'll sit at 100% all day and night long without breaking a sweat, which is what you want for constantly gaming, or systems that are rendering video around the clock. The only minor concern was the 3.3v rail was running around 3v, but in modern systems that's really a non-issue these days. Actually, it's a trend I'm going to have to research a little more too, as I'm noticing this result in other modern units, but overall, I've never actually seen it cause any problems either, as the 12V and the 5VSB seem to be key to system performance these days, as motherboard systems just convert everything on the motherboard. Should I Buy One? With great quality components, and DC-to-DC topology, it's unlikely you'll suffer from excess heat, noise, or coil whine from this unit, which is obviously what we all want from a power supply. 850W isn't enough power for my needs, but for most high-end GPU systems with a decent gaming CPU, 850W is plenty, and should you run into any power spikes, it'll soak them up with ease. Finally, those premium individually sleeved cables are the cherry on top, making this look and feel like a premium product worthy of showing off.