Seasonic X-Series 850W KM3 Power Supply Review

1. Introduction2. Seasonic X-Series 850W KM3 (Bundle & Cables)3. Seasonic X-Series 850W KM3 (External)4. Seasonic X-Series 850W KM3 (Internal)5. Seasonic X-Series 850W KM3 (Super High Res Gallery)6. Testing Methodology7. Closing Thoughts8. View All Pages

Seasonic are using a very high grade 120mm Sanyo Denki San Ace fan (9S1212F404). This fan uses dual ball bearings to enhance life span and reliability. It is constructed around 7 blades which are sculpted to reduce noise while maintaining a high level of airflow. This same model was also incorporated into the KM2 supply. We have no complaints as this is genuinely one of the best fans that money can buy.

Seasonic are using a new fully modular design and the overall build quality is exceptional. This is a full bridge design compared to the half bridge design on the KM2. This should help improve reliability and efficiency even further. We noticed MOSFET on the daughter card, instead of the main PCB which helps to improve the space utilisation to improve cooling efficiency. There are several little rows of heatsinks to ensure adequate cooling reaches the critical components.

The outputs of the unit are monitored by an integrated circuit which supports over voltage, under voltage and over current protection. There are four OCP channels, two for +12V, one for +5V and another for +3.3V.

Seasonic are using high grade Japanese capacitors throughout the design. The primary stage capacitors are Nippon Chemi Con, rated 420V 330uF @ 105C. Secondary stage capacitors are also high grade 105c rated. This is a power supply focused on quality and subsequently no corners have been cut.

Become a Patron!