Corsair CX430M PSU - Introduction

When Corsair entered the PSU market, they have done so by releasing the then high-end HX520W and HX620W units. Much of the company’s great reputation among enthusiasts has been credited on these two products and their successors. However, Corsair apparently was not satisfied with just a piece of the top-end PSU market pie and, about a year after their first units hit the store shelves, released the mainstream TX and GS series, followed by the basic CX and value VS series. It is obvious that Corsair is not only trying to make profit from a couple of popular products but to gain a dominant foothold in every segment of the personal computer PSU market. Here in Legit Reviews, we already had a look at several of their high end and mainstream/gaming products; examples include the monstrous AX1200i, perhaps the best power supply that money can buy even 10 months after its initial release, the high performance AX860 and the professional series HX850, all of which shared exemplary performance and quality – as well as hefty price tags. Today we are going to make a move towards the other end of the market and have a look at the CX430M; a modular power supply from Corsair’s basic series.


Although the CX430M is a power supply capable of delivering up to “only” 430W, it also carries an 80Plus Bronze certification, is of a modular design and comes with a 3 year warranty; all for $24.99 including shipping, after rebate. With Corsair’s reputation on reliability and user support, we can see how this price tag for such a product can be very attractive to common users, casual gamers and system builders. How well can it do in terms of performance, especially under heavy stress? We will find out in this review. 

CX430M fan logo

Corsair CX430M features

Corsair CX430M specifications


Three years


5.9"(W) x 3.4"(H) X 5.5"(L)




430 Watts

80 Plus


ATX Connector


EPS Connector


PCI-E Connector


4 Pin Peripheral Connector


SATA Connector


Floppy Connector



100,000 hours

Unboxing the CX430M

The box

Corsair supplies the CX430M in a bright black and white box with green theme accents. As well as aesthetically pleasing, the box is very sturdy, a rare sight among products of this price range. Inside the box we found the power supply sandwiched between polystyrene foam pieces.

The box (rear)

The rear side of the box is nearly entirely white and comes littered with detailed information on the features and specifications of the CX430M, in no less than six languages.

Bundled items

As expected, in order to keep the retail price as low as possible, Corsair kept the bundled items down to nearly the bare minimum possible. Besides the necessary A/C power cable, the modular cables and the mounting screws, Corsair only supplies a handful of basic cable ties along with the CX430M. It is noteworthy to mention that all of the modular cables are all-black, “flat-type” cables.  

External Design of the CX430M

The Corsair CX430M PSU

Even though the CX430M is being marketed as a basic model, it did not stop Corsair from performing several aesthetic enhancements. The regular ATX chassis of the power supply is sprayed with a soft matte paint, just like the mainstream series products which Corsair currently offers. Decorative stickers can be seen on both sides of the chassis and the center of the otherwise standard circular finger guard is occupied by a large company logo.

Side stickers

As we mentioned above, decorative stickers have been installed on both sides of the CX430M; the chassis however is entirely plain, lacking the embossed lines and patterns of the high end models. The CX series stickers are black with neon green accent, as is the series theme color.

Top side sticker

As is usually the case with Corsair’s products, the sticker with the electrical specifications of the CX430M can be found at the top side of the chassis, where it will only be visible if the power supply is installed at the bottom of a case and facing downwards.

Rear Side

The CX430M is a semi-modular power supply, meaning that the essential 24 pin ATX and 4+4 pin EPS cables are hardwired to the body of the unit, while the rest of the cables are modular. As this is a low output product, we were unsurprised to see only four connectors, three for Molex and SATA cables and just one for a PCI express cable.


It is interesting to note that even though the ATX cable is making use of typical color-coded wires and black sleeving, the hardwired 4+4 pin EPS cable also is a “flat-type” sleeve-less cable with all-black wires. We were glad to see that Corsair is trying to alleviate the aesthetic issue most semi-modular power supplies with flat modular cables have, which is that the hardwired cables usually are typical sleeved cables and the visual difference is obvious and unappealing; however we certainly did not expect to see this happening on a $25 unit!

Front Side

The front side of the CX430M is pretty standard for any performance power supply, with a typical A/C power plug and a small on/off switch.

A look inside the CX430M

The cooling fan

A common black Yate Loon 120mm fan is responsible for the cooling needs of the CX430M power supply. The D12SM-12 is a typical sleeve bearing fan with a maximum speed of 1650RPM.

Inside the Corsair CX430M unit

Identifying the OEM behind the CX430M could not have been any easier than this; even if the green transformers would not reveal it right away, the initials of Channel Well Technology (CWT) are printed on the 5VSB transformer. CWT is a company which has strong bonds with Corsair, having produced many of their medium and high performance units in the past. The heatsinks of the CX430M are quite basic, which is to be expected from such a product; still, they should prove more than sufficient for the low capacity and good efficiency of the CX430M. The soldering and assembly quality are unexceptional but acceptable.

The filtering stage

Most very cheap power supply offering can be identified by their crippled filtering stage. The CX430M is no such product, having a full and “by the book” transient filter which starts at the back of the A/C receptacle and continues onto the main PCB. In total, there are four Y capacitors, two X type capacitors, two chokes and a MOV.

Primary side

The heatsink at the edge of the PCB holds the active PFC components, two transistors and a diode. A Matsushita (Panasonic) 400V/180uF capacitor and a single large coil form the passive components of the APFC stage, with the controller on the vertical daughterboard. The primary stage transistors can then be seen on the heatsink at the primary stage of the power supply, forming a half-bridge configuration.

Secondary side

The electrolytic capacitors on the secondary side of the CX430M are a mix of Teapo and CapXon products, known and reputable manufacturers. Of course enthusiasts would ask for capacitors from companies such as Rubycon and Nippon Chemi-Con; however these would likely cost as much as the whole PSU itself. There are no DC to DC conversion circuits or any other system of note to discuss about the secondary side of the CX430M, as the design probably is nearly as simple as it gets. 

Test Setup

The load


In order to be able to effectively and efficiently test any computer power supply unit, we developed and constructed our own proprietary testing station. Our testing station consists of a number of power resistors and small capacitors, which in turn are connected to a RS485 electronic relay array which allow our load to be controlled through computer software alone.


USB interface and connection panel


When accuracy and speed are of critical importance, a simple multimeter or voltage meter is not sufficient for the task. To ensure the quality of our testing, an USB laboratory interface is being used to continuously monitor and record the readings of all voltage lines simultaneously. For ripple measurements, an oscilloscope is necessary and we chose the USB Instruments Stingray, the most widely used oscilloscope amongst low voltage PSU engineers and testers.


Measurement instruments


For accurate testing and repeatable results, a stable power input is also required. Thus, we are providing power to our test samples through a 3kVA VARIAC which allows us to control the input voltage of our test samples and also perform efficiency tests under both 110V AC and 230V AC input. A Lutron DW-6091 is also being used, monitoring the input voltage, real and apparent power, power factor and amperage.


The software


A power supply testing procedure would not be complete without thermal and acoustics tests. For our acoustics tests we are using a SL-5868P digital sound level meter, placed 1 meter away from the unit (DIN standard). Two PT100 sensors and their respective displays are being used to monitor the ambient temperature and the exhaust temperature of the unit.


Complete test setup during trial run



Testing results (Regulation & Ripple)





We could classify the electrical performance as above average if the CX430M was one of the mainstream gaming/professional units we usually test. For a budget level product however, it simply was outstanding. There is virtually minimum voltage ripple, with our instruments measuring only up to 18mV on the 12V line even at maximum load. Voltage regulation is excellent too, with the 12V line displaying a difference between 20% and 100% load of less than 1.4%. The regulation of the minor 3.3V/5V lines lands at about 2.5%, a clearly higher but still good figure.

Testing results (Efficiency, Noise & Thermal)


Even if only barely, the Corsair CX430M does meet the 80Plus Bronze certification efficiency requirements. The efficiency of the power supply never dropped below 82% and reached up to 85.1% under nominal load while it was being powered by an 110V A/C source, which is just shy of the 85% limit it had to reach for the 80Plus Bronze certification.  


The low capacity of the power supply, combined with the good efficiency, allows it to generate very little amounts of heat. As little amounts of heat need to be dissipated, the cooling fan does not have to spin too fast, even if the heatsinks sport little surface area. This combination allows the CX430M to remain virtually silent across its entire capacity range, reaching audible figures only after running at >80% load.


As the power capacity of the CX430M is rather low, we did not expect great changes in temperature. Truly, the exhaust air temperature of the unit is less than a single Celsius degree higher than that of the ambient air while the power supply is mildly loaded. As the load increases, so does the temperature delta, reaching however only up to 5.6°C at maximum load. 

Corsair CX430M PSU - Conclusion

We were glad that we had the opportunity to test one of the basic products from a respectable manufacturer today and see firsthand what a good engineering team can deliver to the market with just a few tens of dollars. It is a fact that the largest percentage of users do not require power supplies any bigger than the CX430M; as long as it is a common home/office PC or even a gaming PC with a mainstream graphics card, the 430 Watts of the CX430M are more than adequate. Technologically, the CX430M is not really a cutting-edge product. No solid-state capacitors have been used in the CX430M and there are no DC to DC conversion circuits. That however does not mean that the power supply lacks the potential to perform well enough or maintain a high level of reliability. Quite the contrary; we have to admit that the electrical performance of the CX430M was better than we expected from a PSU of such a price range and we could easily compare it to that of much more expensive and powerful products. Electrically, only the efficiency figures are cutting it close, barely satisfying the 80Plus Bronze certification of the CX430M, but we cannot really complain as long as the power supply fulfilled its specifications. Due to the low power output and good efficiency, little heat is generated, which translates to both respectable thermal performance and very low noise figures.

Internal design CWT

Quality wise, the Corsair CX430M is much better than most people would expect from a power supply which now ships for $24.99 after rebate and a $10 off coupon. (Note $10 off code EMCYTZT3255 ends 4/11/13) We cannot claim that it has been built like a tank; we have certainly seen better but certainly not in a $25 product. Still, Corsair cooperated with a highly respected OEM, CWT, the circuit design is that of a “by the book” APFC unit without the companies cutting corners on filtering and or safety and, finally, the choice of components was excellent for a product of such a class. For instance, we did not expect to see capacitors from known manufacturers at all, let alone a Japanese main capacitor! Regarding the secondary electrolytic capacitors from Teapo and CapXon, both companies are reputable manufacturers and their products are being used in many middle-range power supplies. We realize that enthusiasts would prefer capacitors from other (mainly Japanese) companies but there is only so much a designer engineer can do when working under such a tight budget.

CX430M body

The virtually only drawback of the CX430M is that the upgrade room for gamers is limited. Four SATA connectors and three Molex connectors usually are enough for common home and business PCs, where the installation of more than 4-5 drives is extremely rare; however, the CX430M offers only a single 8-pin PCI Express connector, meaning that the CX430M can power only a single graphics card with one PCI Express connector or, by using an adapter, with two PCI Express connectors, as long as one is a 6-pin connector and two Molex plugs get sacrificed. Such graphics cards today are very powerful and capable of offering great frame rates at high resolutions, yet the gamer will never be able to upgrade towards an SLI/Crossfire solution in the future; at least not with high-end graphics cards. We do have to admit however that it is highly unlikely that a gamer would ask for more than that from a 430W power supply, especially expecting it to power two $400+ cards!


Legit Reviews Value Award

Legit Bottom Line: With its performance, warranty and modular design, at $24.99 including shipping after rebate, the Corsair CX430M is far beyond the point of a good bargain; it is a steal. We highly recommend it to anyone building a standard home/business PC or even to those looking to buy a couple of backups.