Corsair AX850 850W 80+ Titanium PSU Review

Corsair AX850 850W PSU Review


The world of power supplies is a lot more interesting than a lot of people think. Yes, a PSU upgrade will not improve your benchmark scores or reduce the frametimes of your favourite games, but that doesn’t mean that the PSU scene isn’t full of room for innovation. 

Last year, Corsair unleashed their AX1600i power supply, pushing the industry forward by delivering 1600 watts of power, an 80+ Titanium rating and a form factor that is smaller than the company’s older AX1500i. 

Out of all of the PSU companies out there, Corsair is the one that perhaps shows the most pride in their units, selecting their components with care to help deliver optimal performance in every category. With the AX1600i this required them to move beyond silicon, transitioning to Gallium Nitride to keep their 1600W monster within a small form factor while delivering chart-topping efficiency levels. 

The AX series is Corsair’s leading PSU brand, which is reserved for the best units that the company produce. The new AX850 revives that brand, moving their sub-1000W AX brand into the era of 80+ Titanium, the highest efficiency rating that’s available for consumer PSUs. The AX850 is designed to impress, which is why our testing started within hours of getting this unit through our door. 

Corsair AX850 850W PSU Review  
Features and Specs – Where’s the i?

As the name suggests, Corsair’s AX850 is not an i-series power supply, preventing the unit from being monitored by utilities like Corsair’s iCue software. Some users may not like this feature omission, though many PC builders don’t mind, especially those of us who don’t care how many wats the PSU is delivering at any given time. 

Corsair’s AX850 boasts a ten-year warranty, ensuring that the PSU will stay within your system longer than any other component. Not many parts remain within the PCs of most tech enthusiasts for ten years, making this warranty a huge statement, albeit one that is now common among high-end power supplies. 

On the rear of the PSU sits a bottom which defines the AX850’s fan profile, offering a semi-passive mode and an always-on fan mode. ALways on mode will keep the fan spinning at all times, maintaining low fan speeds under most situations, ramping up and down depending on the unit’s load. In passive mode, the PSU’s fan will only be switched on when specific thermal conditions are met, but in our testing, the fan didn’t turn on after 20 minutes of running under 100% loading (850W). At this point, our SunMoon PSU tester was warmer than the AX850, showcasing the benefits of this unit’s efficiency in action. 

While this test was conducted in an open-air test environment, in a room which sat at around 22 degrees, 20+ minutes is a long time to sit at 100% load without the need for active cooling. If the fans can stay off for that long, just imagine how slow this unit’s fans would need to spin to keep its thermals under control indefinitely. The AX850 has blessed out ears with silence.    

Corsair AX850 850W PSU Review  
Aesthetic Options

Just like the AX1600i, Corsair’s AX850 ships with four default colour options, black with the unit’s stock grey logo or black with one of the unit’s three AX850 magnetic badges. 

These magnetic stickers can be placed on either side of the PSU, covering the unit’s stock logo or specifications sticker on the other side. At stock, White, Red and Blue options are available, but the modders amongst you should be able to create custom stickers if your desire other colour options. In theory, you can stick anything you want on top of the unit’s supplied stickers, while keeping the core unit pristine to maintain the power supply’s 10-year warranty. 

Our only problem with the AX850 aesthetically is its lack of individually sleeved cables, though this is something that is somewhat forgivable due to the sheer number of cables that this power supply ships with at stock. Sleeving every cable in the box wouldn’t be cheap, and users can always purchase Corsair premium cable kits or 3rd party kits from retailers like CableMod if they wish.  

Power Cables – How many of each are available?

The AX850 ships with everything you will need to build a high-end system of pretty much any sort. Need extra CPU power, have two EPS connections, multiple GPUs, here are six PCIe cables. Let’s face it, who needs sixteen SATA connectors? Not many PCs need more than 850W of total power, but pretty much regardless of your configuration, are unlikely to need more cables than what the AX850 can supply. 

– 1x ATX Power Connector (24-pin)
– 2x EPS/ATX12V Connectors (8-pin/ 4+4-pin)
– 6x PCIe Connectors (6+2-pin)
– 2x 8x SATA Power Connectors (Straight + Right Angled)
– 6x Peripheral/Molex Connectors
– 1x Floppy Adapter


Corsair AX850 850W PSU Review