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Cooler Master MasterWatt Maker 1200 MIJ PSU Review

Our Verdict

The most expensive desktop PSU to date features top build quality and a unique platform. However, for the same amount of money, you can buy a couple of high-end PSUs offering better overall performance and still have cash leftover. Hopefully we'll see more economical models in the future from Cooler Master and Murata.


  • Full power at 47 °C
  • Efficient
  • Build quality
  • Ripple suppression
  • Load regulation
  • Hold-up time
  • Accurate Power Ok signal
  • Silent
  • Quality caps
  • Fully modular
  • 12x PCIe connectors
  • Loop Bearing fan
  • Complete protection features set
  • Warranty


  • Price
  • 3.3V performance
  • OCP at 5VSB is set sky-high
  • Low PF
  • 5VSB efficiency
  • Dimensions

Features & Specifications

Murata Manufacturing is a giant company that designs, manufactures, and supplies advanced electronics. Its products are not budget-oriented. Rather, they boast high quality and enjoy an overwhelmingly positive reputation.

Before now, Murata was already involved in the AC-DC power supply market. But it previously only manufactured server type, open frame, LED lighting power modules, and enclosed front-end PSUs. This is Murata's first time designing and building a desktop PSU, and we're anxious to see the final result. We just hope this isn't a one-off effort, and that Murata hits the PC power supply segment with more models moving forward. It goes without saying, but more OEMs means more choices for companies like Cooler Master.

Increased competition typically makes good power supplies more affordable, though in this case we're looking at a really expensive PSU. Hopefully the MasterWatt Maker 1200 MIJ lives up to the expectations set by its $1000 price tag.

Cooler Master claims that over 160,000 hours were spent by 40 Murata engineers on the project that led to this PSU's creation. Initially, the platform was supposed to be fully digital. In the end, though, they went with an analog platform sporting some digital parts.

This is a strange design choice for a power supply purported to be the best of its generation and an example for future implementations. In our opinion, fully digital platforms are the future of PSUs because they facilitate tighter load regulation and higher efficiency. At the same time, a digital platform is able to balance significantly more variables than an analog one thanks to all of the analog-to-digital converters a modern MCU offers. In conjunction with a capable processor, the architecture can achieve notably improved performance under transient loads.

The only major downside of digital circuits is their higher cost, which should start falling as the PSU industry embraces them more broadly. Complexity tends to increase as well, and that could affect reliability over time. But once there is enough cumulative experience manufacturing digital platforms, we believe that reliability will reach the levels of today's best analog platforms, too.


Efficiency is as good as it gets based on the 80 PLUS organization's scale. Nonetheless, in the fresh ETA certification which is based on a much stricter methodology the PSU doesn't do so well, because of the decreased efficiency on the 5VSB rail and the low PF. Normally it should be rated as ETA-A+ but because it didn't meet both the 5VSB and PF limits, it lost several categories. 

Moreover, fully modular cabling is used, and the suite of protection features includes everything you could hope for.

Cooling is handled by a 135mm Silencio fan that uses a loop dynamic bearing. Cooler Master shared a schematic with us, and, according to its data, the LDB looks to be a fluid dynamic bearing derivative. CM claims that this type of bearing should last for at least 160,000 hours, which would be more than 18 years of consecutive 24x7 operation.

The MasterWatt Maker 1200 MIJ's dimensions are huge, starting with its 224mm depth. The plain MasterWatt 1200 Maker PSU is already large at 200mm-deep. We don't have any problems with large PSUs, though. In fact, we don't really care for compact, high-density power supplies since they're typically also loud. With that said, a PSU this long will undoubtedly complicate the installation process, and it simply won't fit in some enclosures.

Power Specifications

Max. PowerAmps25251003.50.5
Total Max. Power (W)1200

The minor rails provide up to 130W of maximum combined power, while the +12V rail delivers up to 100A if needed. Finally, the 5VSB rail is strong enough with its 17.5W capacity. We like seeing PSUs rated for more than 3A at 5VSB.

Cables & Connectors

Modular Cables
DescriptionCable CountConnector Count (Total)AWG
ATX connector 20+4 pin (700mm)1118-22
4+4 pin EPS12V (690mm)1116
4+4 pin EPS12V (810mm)1116
6+2 pin PCIe (760mm)4416
6+2 pin PCIe (610mm+120mm)4816-18
SATA (550mm+110mm+110mm+110mm)41618
Four-pin Molex (550mm+110mm+110mm+110mm)2818
Four-pin Molex (450mm+90mm+90mm+90mm) / FDD14 / 118-22

The number of PCIe connectors that this PSU offers is amazing, even in its 1200W category. Moreover, you get plenty of SATA and four-pin Molex connectors, while the two EPS connectors ensure compatibility with all high-end motherboards. Given its capacity and cable count, the MasterWatt Maker 1200 MIJ can serve as the foundation for a potent gaming system or workstation with multiple graphics cards installed.

Cooler Master's cable length is satisfactory, though we would like to see more distance between the SATA and peripheral connectors (at least 15cm). The EPS and PCIe connectors use thicker wires for lower voltage drops, while the other connectors employ typical 18-gauge wires.

Power Distribution

Since this PSU features a single +12V rail, we do not have anything to say about its power distribution.

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