Cooler Master GX III 850 Gold 850W PSU Review

Introduction and Specifications

Meet Cooler Master’s new GX III 850 Gold 850W Power Supply

Cooler master are giving their power supply lineup a revamp, and this time they are focusing on power efficiency. Normally, we see companies simply target one of the 80+ efficiency ratings, but this time Cooler Master are taking a different approach. This time, Cooler master are targeting higher levels of low power draw efficiency, something that will boost system idle efficiency. At low loads, Cooler Master’s GX III 850 Gold is an 80+ Titanium power supply, an appealing trait given how often our PCs are idling.

With a 10-year warranty, Cooler Master makes it clear their new GX III Gold series PSUs are made to last. The PSU is semi-fanless and features 100% Japanese capacitors. It even uses an anodised heatsink to deliver improved thermal performance and increased hardware longevity.

Rethinking efficiency

If you use your PC for work, you’re probably not using your PC’s power supply at its rated capacity under most scenarios. Internet browsing and general office work are not power-intensive, and that means that your PC is often sitting at the lower end of your power supply’s efficiency curve.

Looking at the 80+ Gold power supply efficiency standard, power supplies are expected to deliver 88% efficiency levels at 20% load, 92% efficiency levels at 50% load, and 88% efficiency levels at 100% loads at 230V. Under low loads, your PC is likely to be using only a few hundred watts of power. That means that your PSU is not running at peak efficiency.

Cooler Master has designed their new GX III Gold series of power supplies to target higher efficiency levels under low loads. Cooler Master has stated that their GX III 850 delivers 80+ Titanium efficiency levels under low loads, with 90%+ efficiency levels at 10% loads. Our testing showed 92.1% efficiency levels at 20% loads, which is well ahead of the 80+ Gold standard.

GX III 850 Gold Specifications and Cables

Cooler Master’s GX III 850 Gold is an 850W ATX 3.0 power supply that is PCIe 5.0 certified and features both an 80+ Gold efficiency rating and a Cybenetics Platinum efficiency rating. This PSU also has an A- Cybenetics noise level certification.

Out of the box, the GX III 850 Gold ships with a 610mm long ATX 24-pin power cable, a 600mm long EPS 4+4 cable, a 600mm long EPS 8-pin cable, two 8x SATA cables, a 4x Molex cable, three 550mm long PCIe 6+2-pin cable, and a single 650mm long 12VHPWR cable. Since this PSU’s 12VHPWR cable 12VHPWR on both ends, it can be easily replaced with custom CableMod cables if required.

Simple packaging

Packaging-wise, Cooler Master’s GX III 850 Gold doesn’t offer us a premium unboxing experience. The PSU and its modular cables come in separate plastic bags and with minimal flair. Components are adequately protected from potential damage during shipping. The packaging is also easy to remove, which means that it won’t take long to move this unit from its box and into your system.

All of Cooler Master’s cables are black ribbon-style cables that a suitably long for ATX/EATX sized PCs. Sadly, these black cables do not match this PSU’s 12VHPWR cable, which is not a ribbon-style cable and is braided. This isn’t a big deal, but it is worth mentioning.

Angled 12VHPWR cable

Cooler Master has designed the 12VHPWR cables on their power supplies to be more durable cooler-running than standard power cables. Cooler Master’s new 90-degree 12VHPWR cables use connector pins that are 25% thicker than standard 12VHPWR connectors. They also feature four total contact springs. That’s two times as many contact springs as standard 12VHPWR connectors. With these changes, Cooler Master says that their connector is 5 degrees cooler running than standard 12VHPWR terminals, requires a 12% higher withdrawal force, and has an impedance change rate that is 45% lower.

These new 12VHPWR cables from Cooler Master aim to give users improved safety and lower temperatures. The cable’s 90-degree bend is also intended to prevent cable wear from tight bending.

The downside of angled 12VHPWR connectors is that there are two ways a 12VHPWR connector can be oriented on a graphics card. This means that there is the possibility that Cooler Master’s angled cables are oriented in a sub-optimal way for your system.

Above and below we have two RTX 4090 graphics cards. Both use 12VHPWR connectors. One will see Cooler Master’s angled cables pointing upward. The other will see it point downward. This could be a nightmare for aesthetics-focused PC builders. Thankfully, CableMod’s custom 12VHPWR cables are usable with these new PSUs, which means you can replace this cable with ease.