Overclock3D.Net :: Print Page :: Seasonic M12 600w Modular PSU

Seasonic have chosen to keep things plain and simple, using inoffensive green and yellow colour scheme with a picture of the PSU on the front of the box. Flip the box over and we can see that Seasonic have printed some of the units most notable features. These include: up to 85% efficiency, voltage fluctuation of 3% or less, 3 year warranty, quiet dual fans and much more.

On the side of the box Seasonic have placed a specifications sticker that details the amperage output on each of the M12's rails. There are also illustrations on how the dual fan technology works along with a diagram of the modular cabling system.

The M12 is packaged in a single walled cardboard box and is protected from knocks and scratches by a bubble-wrap bag. Hopefully this will be enough to keep the unit safe from the perils of the most brutal couriers.

Included in the box are the following items:
• 4x Silver ATX screws.
• 1x Power cord.
• 1x M12 manual
• 1x Pack of modular cables
• 1x M12 600w PSU

The Seasonic M12 is powder coated in matt black paint and has a minimal amount of shine. Contrasting with the black body is a silver fan grill responsible for protecting the 120mm fan installed on top of the unit.

The back of the unit has the usual honeycomb grill as seen with almost all power supplies that utilise a 120mm fan. This allows for the hot air circulated by the fan to exit out the back of your PC case. You may also notice the abundance of a voltage selection switch. This is because the M12 is able to detect the input voltage (110/240v) and switch accordingly.

The sides of the M12 are fairly plain, with one side containing a specification sticker detailing the amperage output of each rail on the M12, along with all the usual certifications and warnings about opening the PSU's casing.

The front of the unit offers a fresh talking point - a 60mm fan covered with a silver fan grill. This was put in place to give airflow to the areas of the PSU that the 120mm does not reach, and also to assist in the extraction of hot air through the mesh at the back of the PSU.

The front of the unit also sports 7 modular power connectors, 2 of which are dedicated to providing power to PCI-Express cards. Like many other modular units, Seasonic have decided not to make the ATX and P4/EPS power cables modular.

Seasonic have gone for their own proprietary 5-Pin flat connector design for use with the Molex and SATA connectors, but have stuck with the tried and tested 6-Pin PCI-E style connectors for powering the PCI-E cables. On attempting to plug in one of the SATA cables I encountered an issue where the connector backplane was able to flex, and thus prevented me from inserting the modular cable. A video recording of the issue can be seen here.

After further investigation, I managed to find the cause of the issue. The backplane had been designed to sit in front of a lip on the bottom of the power supply casing (as can be seen here), but somehow had managed to come loose. This may well be an isolated issue, but it would be good to see a more sturdy design implemented as the connectors are often subject to a fair amount of abuse.

A total of 9 modular cables are included in the box, but it is worth noting that only 7 of these can be plugged into the unit at any one time, leaving two of the cables redundant. All connectors on the M12 are finished in black, with the molex connectors adopting the 'easy grip' design. It's also good to see that Seasonic have decided to sleeve all cables right to the very last connector.

As the use of floppy disk drives is now declining, the majority of us no longer require floppy style power connectors and would rather an extra Molex or SATA connector instead. Seasonic have realised this, and decided to make the usage of floppy disk power connectors optional by supplying them on a separate Molex-to-Floppy extension cable.

The ATX connector on the M12 is native 24-pin. However, as you can see above, a small block of 4 connectors can be broken off to switch the connector to 20-pin, and thus make it compatible with older motherboards.
As many motherboards still make use of the P4-12v 4-Pin connector, Seasonic have chosen to include two separate cables for P4-12v (4-pin) and EPS12v (8-pin) standards.

From the images above, we can see that the M12 has two yellow transformers placed on the centre of the board. The larger of the two is most likely responsible for the +12v rails with the smaller being responsible for +3.3v and +5.0v rails. Placed in between the transformers is a single, reasonably sized black capacitor.

Turn the PSU around, and we can see two wire-wound inductors sitting below one of the large 'claw' shaped heatsinks. Inductors perform a similar role to capacitors and assist in providing steady, clean voltage to the components in your computer system.

As previously mentioned, the S12 makes use of two fans manufactured by ADDA (1x120mm and 1x60mm) in order to cool all components inside the unit. The specifications of these fans can be seen below:

Model: AD0612HB-D71GL
Size: 60mm x 60mm x 15mm
CFM: 16.6cfm
dBA: 32.4dba
RPM: 4500rpm

Model: AD1212HB-A71GL
Size: 120mm x 120mm x 25mm
CFM: 85.2cfm
dBA: 39.1dba
RPM: 2200rpm

More information on ADDA fans can be found here.

The M12 proved to have very stable voltages on its +3.3 and +5v rails when placed under load. No fluctuation what so ever was exhibited on the +5v rail and a minimal amount of fluctuation (0.02v) was seen on the +3.3v rail.

All of the +12v rails on the M12 told exactly the same story. No change in Idle and Load voltages was seen, placing this power supply among some of the most stable units we've ever tested here at OC3D. I certainly wasn't expecting these kind of results from the M12 and actually tested the unit several times to ensure that our test equipment wasn't faulty!

Efficiency Testing

Efficiency tests are performed by measuring the wattage consumed by the power supply at the mains against the power (in watts) consumed by the OC3D power supply stress tester. These results may not be 100% accurate, but have proven to be extremely close to results obtained from professional equipment.

The M12 was placed under a load of 646 watts. This counts for a total of 107% of the power supplies rated output. At this load, the power supply required 771 watts from the mains. Therefore the efficiency of this power supply can be found by a simple equation: (646 / 771) * 100, which works out to be an efficiency rating of 83.7%.

Noise Testing

Possibly the hardest part of any PSU review is summarising the level of noise given out by the unit. The threshold for what is considered 'noisy' varies from person to person and therefore what I may consider a quiet unit, another person may consider extremely loud. A common way to resolve this issue is to use a dBA meter to measure the units noise level, however this doesn't take into account the pitch (type) of noise emitted and whether it is likely to irritate end users.

For this reason OC3D records all power supplies at idle and load in wav format for you to make your own informed decisions. All recordings are taken at 30cm away from the PSU and outside of a PC case. You will need to remember that noise levels will be reduced by varying amounts once the PSU has been installed inside your PC enclosure.

Idle Recording - Download
Load Recording - Download

After hearing good things about the Seasonic units with regards to noise levels, I was expecting the M12 to be a very quiet power supply. However, these expectations started to turn into concerns once I had seen the choice of fans used inside the unit. With two fans rated between 32dBA and 39dBA it became hard to see how these could possibly be considered "Super quiet" as stated on the M12's packaging.

At Idle I started to regain faith in Seasonic's "super quiet" marketing, with the M12 being almost totally silent due to both fans running at very low RPM.

However, once the M12 was placed under load the fan speed increased significantly, and as you can probably hear from the recordings above - made the unit really quite loud. Personally I would find it very hard to recommend the M12 to anybody seeking a silent PSU for their computer.