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Seasonic M12D-750 750W Power Supply Review

Seasonic M12D-750 750W Power Supply Review - PCSTATS
Abstract: It's big, it's black, and it's modular. This 750W power supply unit is actually in the family above the Seasonic S12 II 500W that PCSTATS tested a while back, and has many of the same ratings: it's 80 PLUS efficiency certified, has up to 99% Active Power Factor Correction (A-PFC) and universal AC support (120/240VAC).
 80% Rating:   
Filed under: Power Supply Published:  Author: 
External Mfg. Website: seasonic Jul 22 2009   J. Apong  
Home > Reviews > Power Supply > seasonic M12D-750

Testing the Seasonic M12D-750 Power Supply

Power supplies which employ Power Factor Correction (PFC, or A-PFC) help ensure efficient conversion of AC to DC voltage, and reduce the amount of energy wasted as heat. That means a quieter 120mm fan can be used, and less noise for your ears.

PCSTATS tests power efficiency with the aid of an Extech Model 380803 Power Analyzer. The meter is located between the mains 120AC supply and the power supply, and a 120W dummy load is connected to the power supply being tested. Power jitter is measured with a Mastech MS8230B Multimeter at the device power connectors.The power supply looking device is actually the 120W dummy load. To the right is a standard Voltmeter, and in the background the Extech Model 380803 Power Analyzer (with readings for Watts, PFC/KHz, source voltage (AC) and Amperage).

Power Jitter Observations - Motherboard

Voltage jitter is read by accessing the power options displayed in the motherboard BIOS, with the system obviously in an unloaded state. Voltages were read from the BIOS of an Foxconn Mars Intel P35 motherboard.

Power Jitter Observations - Motherboard

Listed Voltages

Lower Voltage

Upper Voltage














In the BIOS, the voltage lines are rock solid stable and do not jump at all. Pretty impressive but then again Seasonic is known for building good power supplies. The readings from the multimeter are virtually the same as what the motherboard BIOS reports.

Seasonic Load Tests Source: Seasonic

When looking at the Seasonic Power Supply test results we see two values, wattage and volt-amps. Since it might not be clear what they measure, here's a brief overview.

The volt-amp (VA) value is how much real power is being consumed by the power supply being tested to provide the wattage (W) value. The higher the VA value is, the more electricity is being used by the power supply. Because no electrical device is 100% efficient, there will always be some loss when converting AC to DC. The closer the volt-amps and wattage figures are to each other, the more efficient a power supply is. This is called the Power Factor: wattage / volt-amps =PF.

Since we're testing with a 120W dummy load, the load on the power supply (wattage) should be as close to this figure as possible. Anything above this load in apparent power describes the overhead and wasted energy (given off as heat) for the particular power supply being tested. For the unloaded tests, the wattage and volt-amp figures should be as close as possible to one another. The lower the figures are, the less power is being wasted. Measurements were taken with an Extech 380803 Power Analyzer.

Seasonic Power Load Tests
Power Supply Model Wattage Test Type Loaded Unloaded
Seasonic SuperTornado 400 W
Active Power 177 W 6 W
Apparent Power 182 VA 7 VA
Vantec iON2 350 W Active Power 192 W 10 W
Apparent Power 277 VA 21 VA
Antec TruePower 330 330 W Active Power 195 W 22 W
Apparent Power 289 VA 38 VA
Ultra X-Connect Green UV 500W 500 W Active Power 193W 22 W
Apparent Power 307 VA 40 VA
AOpen Silent Power AO400-12AHN 400 W Active Power 179W 9 W
Apparent Power 275 VA 18 VA
Seasonic S12-430 430 W
Active Power 179W 6W
Apparent Power 180VA 9VA
PC Power and Cooling Turbo-Cool 510 Express/SLI

510 W

Active Power

200 W

29 W
Apparent Power 202 VA 32 VA
HEC Ace Power 580UB

580 W

Active Power

183 W

12 W
Apparent Power 272 VA 26 VA
HEC Win 550UB 550 W Active Power 184W 10W
Apparent Power 263VA 22VA
Akasa PowerPlus AK-P550FF 550 W
Active Power 194W 38W
Apparent Power 197VA 40VA
AOpen Prima Power AO700-12ALN 700 W
Active Power 172W 3W
Apparent Power 181VA 9VA
PC Power & Cooling Turbo-Cool 1KW 1000 W
Active Power 205W 25W
Apparent Power 207VA 32VA
Seasonic S12 600 600 W
Active Power 164W 7W
Apparent Power 173VA 9VA
Mushkin Enhanced XP-650 650 W Active Power 192W 22W
Apparent Power 279VA 43VA
Seasonic S12 Energy Plus SS-650HT 650 W
Active Power 150W 7W
Apparent Power 150VA 10VA
Seasonic M12 700W 700 W
Active Power 161W 8W
Apparent Power 165VA 11VA
Corsair HX620W 620 W
Active Power 171W 8W
Apparent Power 173VA 12VA
Zalman ZM600-HP 600 W
Active Power 173W 5W
Apparent Power 175VA 9VA
HEC Zephyr 650 650 W
Active Power 185W 12W
Apparent Power 190VA 17VA
GlacialPower GP-PS550BP 550 W Active Power 178W 6W
Apparent Power 269VA 17VA
Cooler Master Real Power Pro 750W 750 W
Active Power 158W 6W
Apparent Power 163VA 9VA
Seasonic S12 II 500W 500W
Active Power 145W 7W
Apparent Power 148VA 10VA
Seasonic M12D 750 750W
Active Power 169W 7W
Apparent Power 173VA 9VA

The Seasonic M12D 750 power supply drew 169W of power when a 120W load was hooked up, which is about 71% efficiency (at that load). There are a few models we've tested, including Seasonic's recent S12 500W, that have achieved 80% efficiency and higher at the same load. The efficiency of the Seasonic M12D-750 may improve if it was possible for PCSTATS to increase the load conditions closer towards it's rated capacity of 750W. However due to the limitations of our testing equipment we've simplified our test to simulating average load conditions for a normal desktop computer.

Efficient Power Supply Triumphs over Vanity

Seasonic 's M12D 750 is a high-capacity, modular 750W power supply that's aimed at the enthusiast, but still manages to be fairly power efficient.

The Seasonic M12D-750's detachable cabling makes it easy to keep your computer case clean and easy to work inside of. Being able to remove cabling when system components are not in use also improves airflow and lowers ambient system temperatures.

Adding in cables only takes a second, and the cables themselves fit quite snugly and stay in place well. It's a genuinely useful feature to have, and the Seasonic M12D-750 takes it a step further by giving users the options to swap between SATA and four-pin molex connectors.

Having the option to plug in as many as 11 SATA cables or up to eight molex connectors, as well as a quartet of eight-pin (6+2) PCI Express connectors means that this power supply has enough plugs to satisfy even the most extreme power users.

Those who are more concerned about efficiency will be pleased to hear that the Seasonic M12D-750 does quite well. While we were only able to push this system with a 120W load (which is about typical for most desktop systems at idle), it still managed to achieve around 71% efficiency, and maintained steady voltages all the way through our testing. During testing the Seasonic M12D-750 was barely audible, and remained cool to the touch over the duration of it being put under load. The fan itself is automatically controlled by the case temperature, so if your PC isn't under stress or load conditions and building up heat it will remain nicely silent.

On top of that, the 80 PLUS rating, Active Power Factor Correction and Universal AC support are just icing on the cake. For $210 CDN ($180 USD, £110 GBP), the 750W Seasonic M12D-750 power supply offers up great value and handy features that make it worth considering.

PCSTATS Recommended Product Award

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< Previous Page © 2020 PCSTATS.com Power Supply Reviews...»


Contents of Article: seasonic M12D-750
 Pg 1.  Seasonic M12D-750 750W Power Supply Review
 Pg 2.  Appearance and Physical Specifications
 Pg 3.  Looking Inside the M12D-750
 Pg 4.  — Testing the Seasonic M12D-750 Power Supply

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