Introduction

We would like to thank Super Flower for supplying the review sample.


Super Flower has been busy preparing its Leadex III line, which faces off against fierce competitors, including the new Corsair RM and RMx models and popular Seasonic Focus Plus units. Having already reviewed the 850 W Leadex III model, I have an idea of what to expect from its smaller sibling which is, with a capacity of 650 W, ideal for a strong single-GPU system.



The SF-650F14HG, or Leadex III 650 W, is a fully modular power supply featuring Cybenetics ETA-A and 80 PLUS Gold efficiency certifications. When it comes to noise output, it has the LAMBDA-A++ certification by Cybenetics, which means it is nearly dead-silent in all states. It is nice to see manufacturers paying a lot of attention to noise output and efficiency. The days of a PSU's noise output being secondary have long passed as most users nowadays want every part of their system to be silent.

Specifications

The new Leadex III models are a bit smaller dimensionally than the previous-generation units. Still, a 135 mm or even 140 mm fan could have been used. Super Flower went with a 130 mm fan instead, which I won't have a problem with if a very relaxed fan-speed profile is used.



This power supply is supported by a semi-passive operation with three operating modes: 0, 1, and 2, which deactivates the passive operation. For a longer passive operation, you should select Mode 0.

Cables and Connectors

There are two EPS and four PCIe connectors, which is plenty for a 650 W PSU. The number of peripheral connectors is satisfactory, but they should be further apart,150 mm.


The cables are long enough, and some of these (ATX, EPS, and PCIe) are equipped with capacitors for lower ripple.

Component Analysis

The primary side uses a half-bridge topology along with an LLC resonant converter to restrict switching losses. The single-sided PCB looks weird as such a PCB is usually only utilized in lower-cost PSUs.


The transient filter only has two Y caps. It should at least have four. The number of other components in this stage is adequate.


This is the unit's PFC circuit. It doesn't do a great job, especially with 230 V input.


On the secondary side, the main FETs are installed on dedicated heatsinks. Right in front of them is a compact transformer, and next to it is the resonant tank.


The fan controller is on a vertical board, with the 5VSB rectifier and transformer that handles this circuit close-by.


Two small heatsinks cool down the +12V FETs.


The VRMs that handle the minor rails.


Soldering quality is not the best I have seen from Super Flower. However, it won't create any reliability or performance issues.


The cooling fan is by Globe Fan and uses a Fluid Dynamic Bearing.