INTRODUCTION

    Power supplies sit at the quiet center of every serious build, shaping stability, efficiency, and long‑term reliability in ways that only become obvious when they’re missing. They translate raw wall power into clean, predictable energy for GPUs, CPUs, and storage, and the best units balance electrical precision with thermal discipline and acoustic restraint. As modern systems draw sharper transient spikes and demand tighter voltage behavior, the PSU has shifted from an afterthought to a core component that defines how confidently a rig can be pushed. Into that landscape steps the latest PlatimaxII 1200DF model by ENERMAX.

   ENERMAX was founded in Taiwan in 1990 and is a world-renowned PC Power Supply manufacturer and maker of award-winning PC components such as chassis, coolers, fans, and peripherals, with recognition from consumers around the world. Our farsighted R&D capability is our key strength, and we stick to our spirit of “Technical Innovation” and “Quality First” to create products that unleash the full potential of the system for every PC enthusiast. For more information, please visit us at www.ENERMAX.com

    The brand new PlatimaxII line of power supply units currently includes only a 1200W output variant available in both black and white colors. This is an ATX 3.1 & PCIe 5.1 compliant and 80 PLUS Platinum certified (up to 92% efficiency) model that features a single 12V-2x6 power connector, three 6+2 pin PCIe power connectors, single +12V rail (100A) capable of delivering 100% of the units’ power output and has a total power output of no less than 1319W (peak should be up to 2820W for up to 100ms - once again however this is not something I can test). Other features and specifications include Full-Bridge & LLC Resonant Converter paired with synchronous rectification and DC‑to‑DC regulation (thus allowing the unit to sustain stable voltage output even under rapid load shifts), active PFC, semi-passive zero-RPM fan mode and dust-free rotation feature for the 135mm fan (starts spinning after a specific load), and a full array of electrical protections including over-current (OCP), over-voltage (OVP), under-voltage (UVP), short-circuit (SCP), over-temperature (OTP), and over-power (OPP). ENERMAX currently offers a very generous 13-year limited warranty for the new PlatimaxII 1200DF.

SPECIFICATIONS AND FEATURES

PACKAGING AND CONTENTS

The latest PlatimaxII 1200DF PSU is shipped inside a cardboard box that has the Enermax logo at the front and a piece of paper with a product picture and the product certifications.

A product description is printed on the right side of that paper in multiple languages.

At the rear we find the electrical table along with several product pictures showcasing the main product features.

Typically, the unit is wrapped inside a synthetic cover and placed between two pieces of foam.

Along with the PlatimaxII 1200DF, it's power cord and modular cables inside the box you'll also find two synthetic covers (PSU, modular cables), 4 cable ties, 5 mounting screws, and the user manual.

THE PLATIMAXII 1200DF EXTERIOR

ENERMAX has used embossed, low profile (for the most part) power cables with the PlatimaxII 1200DF.

The PlatimaxII 1200DF is a compact model measuring just 150mm in width, 150mm in length and 86mm in height.

Using an 135mm fan in such a model is something I always welcome.

The company logo and model name are both printed on the sides.

As usual the electrical table is placed on a sticker located at the base of the enclosure.

All 14 modular power ports are tagged and different in size.

At the rear we find the power port, on/off switch and the dust free rotation mode button.

THE PLATIMAXII 1200DF INTERIOR

The 135mm brushless ball bearing fan is manufactured by Globe Fan.

Shenzhen RSY is the OEM behind the PlatimaxII 1200DF (and other models by Enermax in the past).

The two primary capacitors are manufactured by Rubycon and are certified for use up to 105 degrees Celsius.

Secondary capacitors are manufactured by both Rubycon and Unicon and are also certified for use up to 105 degrees Celsius.

TEST BED

TESTING METHODOLOGY

     Using a dedicated measurement instrument such as a Chroma or a SunMoon to test power supply units is without doubt the most ideal and accurate way (not to mention the fastest) to do that currently. However, it's certainly not the only way there is and so pretty much anyone can test a power supply unit just by using a test rig. Certainly, limitations do apply and so you can't really push a 1000W power supply to its limits if your system only uses 500W at peak loads and that's why over the years we saved certain hardware components for the purpose of building a dedicated PSU test rig. True it may not be as accurate as the above-mentioned solutions, but it comes really close and is in fact much closer to real world usage. So as always, we ran several games with maximum graphic options enabled at a resolution of 2560x1600 in order to stress every hardware component and increase the overall power demands of the system. The Passmark BurnIn Test was also used to overstress the components in an effort to provide the most accurate results possible. As a final test we also used the latest OCCT software and its dedicated PSU testing suite since it can really bring a power supply to its knees after inside a few minutes.

   Rail stability was checked/measured with the CPUID Hardware monitor and a Metex multimeter which also recorded the system load in idle and in load. As always try to remember that the power consumption numbers listed in the graph are the highest (Peak) ones recorded during the entire duration of the tests and not the average ones. Noise levels coming from the fan were recorded using the high precision HD600 ExTech Sound dBA Meter from the rear of the unit and at a range of no more than 5-10cm. Readings under load are recorded the exact moment we manually switch the fans of all graphics cards from full speed to almost zero, that way the fan of the power supply does not have enough time to slow its RPM and so by doing this we get very accurate noise level readings. Needless to say, in order to get 100% accurate readings, you need to have a noise isolated room for that exact purpose, something which is quite impossible unless you are working inside a real lab (some people use very small noise insulated boxes but due to their size both heat and noise exceed normal levels and so the results can't really be considered to be 100% accurate, nor realistic for that matter). Also do take into account that since all noise measurements take place from just 5-10cm away the final noise levels to reach your ears will be considerably less.

* After well over 10 years of testing PSUs the Intel Core i7-920 CPU of this rig failed and so we replaced it with a Xeon X5660 (we also swapped the GA-X58A-UD7 for the G1. Assassin).

TEST RESULTS

CONCLUSION

    The PlatimaxII 1200DF wraps up as a PSU that leans heavily on its core strengths, solid rail behavior, high‑efficiency credentials, and a component selection built for longevity. Its dual Platinum certifications reinforce that it maintains strong efficiency across real‑world load ranges, while the 1200W output and generous power‑excursion tolerance give modern GPUs and multi‑device setups the breathing room they need. The allJapanese capacitors add confidence in long‑term stability, while Enermax includes a full suite of electrical protections (OVP, UVP, OCP, OPP, SCP, and OTP) to safeguard the system when something goes wrong. Rail stability is very good, though not quite at the very top of the category, and as for noise levels under heavier loads they can rise a bit more than ideal without becoming a major drawback. Taken as a whole, it’s a dependable, efficiency‑focused unit that delivers consistent performance and robust protection for demanding builds.

    Currently the ENERMAX PlatimaxII 1200DF ATX 3.1 & PCIe 5.1 power supply unit retails for USD229.99 inside the USA (Amazon.com) and for 178.35Euros inside the EU (Amazon.de) so it’s priced well. Bottom line is that you simply can’t go wrong with the PlatimaxII 1200DF by ENERMAX which is not only why I hope they add more models in that lineup but also why it gets our Golden Award.

PROS

- Good Build Quality
- Very Good Rail Stability
- ATX 3.1 & PCIe 5.1 Compliant
- 80 PLUS Platinum Certified
- 1200W Output
- Dust Free Fan Feature
- Electrical Protections (OCP/OVP/SSP/OPP/UVP/OTP/SIP)
- 13 Year Limited Warranty

CONS

- Single Model In The Lineup
- Overall Availability