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The Enermax PlatiGemini 1200W ATX 3.1 + ATX12VO PSU Review: The Swiss Army Knife

In the retail PC PSU space, most of the focus on new standards and their capabilities in the past couple of years has been on ATX 3.0 and it’s quick follow-up successor, ATX 3.1. And while the revised ATX standard is certainly the most important new standard for the rank-and-file PC builder, it’s not the only standard that has been released as of late. Intel and its partners have also developed a standard, that in some respects, goes even farther out by dropping some of the legacy aspects of ATX and its increasingly esoteric secondary voltages: ATX12VO.

Short for “ATX 12 Volts Only”, ATX12VO is a standard that’s been slower to take off as it makes a pretty hard break with backwards compatibility. But with so many motherboard functions running off of 12V (CPUs and GPUs, for a start), the need for a PSU to provide secondary voltages like 3.3V and 5V just aren’t what they once were 20 years ago – or even 10. So we’ve slowly seen PC manufacturers and motherboard makers test the waters, with a handful of designs using the more petite ATX standard.

Meanwhile on the power supply side of things, the outcome has been a bit more interesting, if messy. While ATX12VO motherboards need matching PSUs, there’s nothing to say that such a PSU can only be ATX12VO. To reference an ancient meme, the thought at some PSU manufacturers has been “why not both?”, leading to high-end PSUs that can bridge the compatibility gap by offering both ATX 3.1 and ATX12VO compatibility.

The first example of such a PSU to make it in our labs is Enermax’s new PlatiGemini 1200W PSU. Designed to be the Swiss knife of modern top-tier PCs, Enermax’s PSU offers support for both ATX 3.1 and ATX12VO – ensuring it can power virtually any PC – while driving both modes with a sizeable 1200W design that can pretty much power virtually any desktop PC one can hope to build today. Plus, with features like fully modular cables with per-wire sleeving, a dynamic hybrid fan control for optimal cooling, and advanced power topologies, the PlatiGemini 1200W aims to deliver both reliability and performance on top of its multi-mode compatibility. The end result is a very interesting (if premium) product that can do it all.

Enermax PlatiGemini 1200W
Power Specifications ( Rated @ 50 °C )
AC INPUT100 – 240 VAC, 50 – 60 Hz

Packaging and Bundle

The Enermax PlatiGemini 1200W ATX 3.1 PSU comes in straightforward yet efficient packaging. The outer box, a simple cardboard design, is visually enhanced with a decorative ribbon. The PSU itself is well-protected during shipping by a nylon bag and dense packaging foam, ensuring it arrives in perfect condition.

The bundle includes more than just the essential mounting screws and AC power cable – a manual, a jump-start adapter, and cable combs are also included.

This PSU features all-black cables, including connectors and wires, with individually sleeved wires, providing the PlatiGemini unit with a premium aesthetic factor. Enermax also includes an ATX12VO connector, which is one of the highlights of this series. Strangely, for the massive 1.2 kW output of the unit, the total number of connectors is fairly low.

Enermax PlatiGemini 1200W
Connector typeHardwiredModular
ATX 24 Pin1
EPS 4+4 Pin2
PCI-E 5.01
PCI-E 8 Pin3

The Enermax PlatiGemini 1200W ATX 3.1 PSU

External Appearance

The Enermax PlatiGemini 1200W ATX 3.1 PSU is housed in a chassis that measures 150 mm in length, slightly longer than the standard ATX dimensions specified by the ATX design guide. This extra length accommodates the 135 mm cooling fan, ensuring better cooling performance and fitting into all ATX-compliant tower PC cases.

This PSU boasts a sleek and subtle design, highlighted by its matte textured black finish. The unit eschews unnecessary decorations, featuring prominent chrome logos on the sides for a clean look instead. The top side is covered with a sticker detailing the electrical specifications and certifications.

The front side of the unit includes the standard on/off switch and AC cable receptacle, as well as a switch for the Dust Free (D.F.) function, which reverses the fan direction to blow dust away. The rear hosts the modular cable connectors, organized for easy and error-free connections. While the connectors are not color-coded, they are labeled with a simple, bright white legend next to each connector, aiding in accurate cable management. A white imprint of the company logo can also be found on the rear side, enhancing aesthetics.


Internal Design

The Enermax PlatiGemini 1200W PSU is equipped with a Zeta Group ZFB132512H 135 mm fan, featuring a ball-bearing engine. This type of fan is known for its reliability and durability, making it a common choice for high-quality PSUs. While ball-bearing fans can be slightly louder at higher speeds, they excel in high-temperature environments. The fan in this model can reach a maximum speed of 1800 RPM, a relatively conservative figure, suggesting that Enermax’s engineers have a lot of faith on this unit’s efficiency.

The Enermax PlatiGemini 1200W ATX 3.1 PSU is produced by Shenzhen Rui Sheng Yuan, an OEM with extensive experience in the power supply industry, despite past reliability issues between 2015-2017. Their long history in power electronics enables them to produce mid to high power output PC power supplies. They seem to be behind at least several of Enermax’s latest units.

This platform is based on well-established topologies, designed with reliability in mind. The input stage features a basic transient filter, consisting of two Y capacitors, one X capacitor, and two filtering inductors. The Active Power Factor Correction (APFC) setup includes two rectifying bridges attached to a dedicated heatsink, supplemented by four APFC MOSFETs (50R140CP), three diodes, a large encased filtering inductor, and two Rubycon 560 μF capacitors. The active components are sandwiched between two plates that also serve as basic heatsinks.

In its primary inversion stage, the Enermax PlatiGemini utilizes a full-bridge LLC topology with high-quality Infineon 50R140CP MOSFETs. Uniquely, the primary side transistors are on a vertical PCB without any heatsink attached directly on them. The secondary stage features eight Infineon 014N04LS MOSFETs, using synchronous rectification for the primary 12V line, with 3.3V and 5V rails generated by DC-to-DC circuits on a vertical daughterboard. There is an extra rectification circuitry to generate the 5VSB and 12VSB voltages, as required for the ATX12VO compliance. The secondary side capacitors are a mix of top-tier Japanese products from Rubycon, Nichicon, and Nippon Chemi-Con, ensuring reliability and performance.