INTRODUCTION

    With today’s GPUs capable of drawing sudden bursts of power far beyond their rated wattage, the shift to ATX 3.1 and PCIe 5.1 power supplies marks a necessary evolution, bringing improved transient tolerance, tighter voltage regulation, and the safer, simplified 12V‑2x6 connector that next‑generation graphics cards increasingly rely on to maintain stability under extreme load swings. These updated standards aren’t just incremental tweaks; they’re a response to the real electrical behavior of modern hardware, ensuring that high‑performance systems can sustain rapid changes in demand without voltage droop, cable stress, or the multi‑cable compromises older PSUs required. The MEGA GM 1000W is the latest ATX 3.1 & PCIe 5.1 model by FSP and that's also what today's review is all about.

    FSP Group is one of the global leading power supply manufacturers. Since its establishment in 1993, FSP Group has followed the management conception “service, profession, and innovation” to continuously fulfil its responsibilities as a green energy resolution supplier. With the combination of its leading role in power supply technology and the cultivation of green energy field, FSP Group now provides more competitive quality products and makes itself the most reliable partner for customers, consumers, and suppliers with joint creation of maximized values.

    Currently the MEGA GM line of ATX 3.1 & PCIe 5.1 power supply units includes 850/1000/1200W output models all of which are fully modular and 80 PLUS Gold certified (up to 90% electrical efficiency). Today I'll be testing the 1000W output variant which features a single 12V-2x6 power connector (600W), three 6+2 pin PCIe power connectors, single strong +12V rail (83.33A) capable of delivering 100% of the units’ total power output (1000W) and a maximum power output of no less than 1138W (peak should now be around 2.3KW for up to 100ms - once again however this is not something i can test). Other features include half-bridge & LLC resonant converter with synchronous rectification and DC to DC design, active PFC, eco semi-fanless mode for its 135mm fan (starts spinning after either temperatures reach 55 degrees Celsius or at 50% load), high-quality Japanese capacitors certified for use up to 105 degrees Celsius, proprietary MTLC® (Micro Tolerance Load Control) design (for ultra-precise voltage regulation within ±1%), exclusive conformal coating (enhanced resistance to humidity, dust, and environmental corrosion) and a full array of electrical protections including over-current (OCP), over-voltage (OVP), under-voltage (UVP), short-circuit (SCP), over-temperature (OTP), surge and in-rush (SIP), no-load operation (NLO) and over-power (OPP). Finally, as with past models FSP covers the entire MEGA GM line of power supply units with generous 10-year limited warranty.

SPECIFICATIONS AND FEATURES

PACKAGING AND CONTENTS

The MEGA GM is shipped inside a black box that has a product picture at the front alongside the company logo and the main product features.

All available power connectors are printed on the left side of the box.

Depending on region the MEGA GM comes with different power cords (indicated on top).

At the rear we find the features list in 10 languages and of course the product electrical table and contact information for FSP.

The interior of the box is made of recycled materials.

Along with the MEGA GM 1000W it's modular power cables and power cord inside the box you'll also find a PSU tester, 3 cable straps, 4 mounting thumbscrews, several cable holders, warranty paper and the user manual.

THE MEGA GM 1000W EXTERIOR

All modular power cables in the bundle feature individually sleeved cables, 12V-2x6 included.

Measuring just 150mm in length, 150mm in width and 86mm in height the MEGA GM 1000W is a rather compact model (always for its output).

The 135mm FDB (fluid dynamic bearing) fan sits under a silver grille.

Typically, the model name and brand logo are printed on both sides.

As usual the electrical table is printed on a large sticker located at the belly of the enclosure.

All 12 power connectors/ports at the front of the unit are different in shape and tagged.

At the rear we find the eco semi-fanless mode on/off switch, power on/off switch and the power port.

THE MEGA GM 1000W INTERIOR

The 135mm fluid dynamic bearing fan is manufactured by Power Logic.

Clean (and almost cable free) layout is exactly what I've come to expect from FSP over the years.

Primary capacitors are by Nippon Chemi-Con and Rubycon and are certified for use up to 105 degrees Celsius.

Secondary capacitors are also by Nippon Chemi-Con and Rubycon 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 FSP MEGA GM 1000W delivers impressively stable rails, a native 12V‑2x6 connector for modern GPUs, and the dependable efficiency of an 80 PLUS Gold platform backed by Japanese capacitors, proprietary micro tolerance load control design and a conformal coating all of which reinforce long‑term durability. Its strong electrical foundation is further supported by a full array of protections ensuring the unit can safeguard both itself and the system during abnormal conditions or sudden load events. Combined with a 10‑year warranty, it feels like a PSU built for users who want reliability they won’t have to second‑guess.

    As I type these lines the MEGA GM 1000W ATX 3.1 & PCIe 5.1 power supply unit retails for around 160Euros inside the EU so no complaints here either. The only real drawback the MEGA GM line has is current availability and well, I sure hope FSP will resolve this sooner rather than later. At the end of the day for anyone prioritizing electrical performance, component quality, and next‑gen readiness, the MEGA GM 1000W justifies its position with confidence and that’s why it gets the Golden Award.

PROS

- Build Quality
- Near Excellent Rail Stability
- 80 PLUS Gold Certified (Up To 90% Electrical Efficiency)
- Electrical Protections (OVP/OCP/OPP/OTP/SCP/UVP/SIP/NLO)
- Micro Tolerance Load Control
- 12V-2x6 Connector (600W)
- Eco Semi Fanless Mode
- 10 Year Limited Warranty

CONS

- Current Availability