Seasonic M12II-620 Power Supply Review

Author:Paul Johnson

Editor:Kyle Bennett

Date: Tuesday , May 18, 2010

Seasonic is back with an old favorite aiming to make it better for the end user by giving you now Bronze level 80 Plus certification. Our tests are more harsh than 80 Plus' tests, so let's see how exactly Seasonic's new M12II 620 watt PSU takes to our more stringent testing conditions.


In the power supply realm when consumers think of quiet and efficient power supplies one of the first company that comes to mind is Seasonic and today we have our fourth crack at a Seasonic branded unit. This review marks the launch of Seasonic's newest line of power supplies the "X Series" with the unit we have here today being the M12II-620Bronze (SS-620GM Active PFC F3).

Seasonic is one of the older companies producing consumer power supplies having been founded in 1975 and entering the PC power supply production market in 1980. During that more than 30 years as a company Seasonic has cultivated lines of power supplies that are today some of the standard bearers for efficiency and quiet computing. This focus, and its reputation for quality, has lead to a real explosion in production as Seasonic can be found providing OEM services on various model lines for Antec, Corsair, PC Power and Cooling, and of course under its own Seasonic brand.

Still a Medal Contender?

The Seasonic M12II-620Bronze is the 4th Seasonic branded Seasonic power supply we have seen to date. The first unit we saw was the S12II-500, some time ago, followed by the much newer designs in the M12D-850 and the X-750. Today's M12II-620Bronze is a bit of a throwback to that first review as this unit is not one of Seasonic's new high-end designs but rather a tweaked older design meant to compete in the more entry level to mainstream product segments. As such, this unit will not only have to perform, and perform well, but also come in at a good price point to be really competitive today. Before moving on to see if it can do those things, what does Seasonic have to say about this unit?

Sea Sonic Electronics launches the M12II "Bronze" Series, the new and upgraded version of the M12II "Bronze" Series in response to the growing demand and anticipation for more energy-efficient products. The M12II Bronze Series inherits the same output and wattage options as well as the superb quality and ultimate silence from the M12II Series. The M12II, available in 500 watts, offers buyers with a mid range power output solution with cable management, to meet their exact system needs; cable management is now made easier than ever.

The M12II Bronze Series achieves the 80 PLUSآ® Bronze standard of at least 82%, 85% and 82% efficiency under 20%, 50% and 100% operating loads respectively. Combined with Active Power Factor correction (Active PFC), the M12II Bronze reduces energy waste, boosts power efficiency and more importantly, helps the users to save energy and reduce electricity bill.

While upgrading in efficiency, the M12II Bronze Series maintains the advanced designs and quality components from the past M12II line. Such designs and components including Double Forward Converter design, Smart and Silent Fan Control and highly reliable Japanese brand capacitor also boost the overall performance in stability and silence. The M12II Bronze Series is available in standard ATX Form Factor and in wattages that are beneficial for a PC system. With the all-in-one cabling design and EPS connectors, the M12II Bronze Series is geared to support IPC and server systems and as well, both 6P & 8P PCI-E connector for latest and high end dual graphic cards. Moreover, the modular design also provides a flexible solution for orderly cable management.

The M12II Bronze Series is made reliable by featuring safety regulations such as Over Voltage Protection (OVP), Short Circuit Protection (SCP), and Over Power Protection (OPP). Major safety and EMC directives and as well, the environmental certifications RoHS and WEEE increase safety and usage reliability for the users.

Now that we know what Seasonic expects from this power supply let’s see what we have to look forward to when we purchase the M12II-620Bronze in terms of documentation, accessories, cable count, rail layout, output characteristics, and general build quality.