Introduction

There are only a few Corsair CX-M reviews since they are budget units, so I thought to do something about it. Corsair upgraded all CX-M units and used their new design with triangular-shaped perforations on the fan and exhaust grilles. The exterior readily distinguishes the new from the old. Today, I will look at the CX650M with enough power to support a mid-level system. The CX650M has the Bronze 80 PLUS and Cybenetics Silver efficiency ratings, as well as the Standard++ Cybenetics noise rating, which is pretty good for its efficiency. The fan uses a rifle bearing, and the 5-year warranty is long enough for a $70 PSU. Lastly, at only 140 mm deep, this compact PSU won't give you any headaches during installation despite its two affixed cables.

The previous line included a 850 W model, but the new one only goes up to 750 W across three unit in total, starting at 550 W maximum power output. All of these feature a semi-modular cable design to lower the production cost and use less advanced platforms than the CX line, which is too advanced for "mere" Bronze efficiency.

Specifications

Photos

On the face of the small box is a photo of the PSU with its fan grille and triangular-shaped perforations. The new exterior design looks nice.


Protection inside the box would be better with more packing foam.


The bundle includes the modular cables and AC power cord, set of fixing bolts, and leaflet with a catchy title.


The exhaust grille also has triangular perforations.


Stickers with the model number are on the sides. The power specifications label is on the bottom.


The modular board only has five sockets. The fixed cables are fully sleeved, and a plastic grommet is on the cable-exit hole.


At only 140 mm long, this PSU is compact.


Here are some more photos of the PSU from various angles.

Cables and Connectors

There are only two fixed cables, and both are sufficiently long.


The single PCIe cable is modular and has two connectors. Corsair didn't want to offer two additional PCIe cables because of the two EPS connectors which can stress the PSU if fully utilized. Lastly, there are enough peripheral connectors, but as per usual for a Corsair product, the distance between peripheral connectors is short.

Component Analysis

Before reading this page, we strongly suggest looking at this article, which will help you better understand the insides of a PSU.



The CX-M line is based on the CWT CSB-A platform, which uses a combination of old and new circuits. On the primary side is a double-forward topology, which is considered outdated. In contrast, the secondary side has been given a modern touch with DC-DC converters for the generation of the minor rails.


The transient filter is complete.


There is an MOV for protection against power surges. An NTC thermistor handles inrush currents.


Finding a discharge IC in a budget PSU is nice.


The single bridge rectifier can handle up to 15 A.


The APFC converter uses two Champion FETs and a single boost diode. The bulk cap is by Chemi-Con. Its capacity is not high enough to reach a 17 ms hold-up time.


The primary switching FETs are installed into a double-forward topology, which is outdated but more affordable to implement.


The combo APFC and PWM controller is a Champion CM6800TX IC—a blast from the past. A Champion CM03X supports it for the low vampire power needs of today.


The unit's main transformer provides electrical isolation between the primary and secondary sides.


A mix of FETs and SBRs regulate the +12 V rail.


Most filtering caps are provided by Teapo, an often-used brand in budget units. Teapo caps are even found in several more expensive implementations since Teapo is considered a good alternative to Japanese cap manufacturers.


Two DC-DC converters generate the minor rails.


The standby PWM controller is a Power Integrations TNY290PG IC.


The supervisor controller is an INI1S429I - DCG.


Soldering quality is good.


The cooling fan is by Hong Hua and uses a rifle bearing. This is a great choice, especially for an affordable unit like the CX650M.

Test Setup