Corsair CX430 V2 Power Supply Review

[nextpage title=”Introduction”]

We were really surprised by the original Corsair CX430, a unit that doesn’t have the 80 Plus certification but is able to present a terrific performance for its price point. Corsair updated the CX430 to include the standard 80 Plus certification and to extend its warranty from two to three years. The good news is that the new CX430 V2 is available at exactly the same price as the original CX430. Let’s see how the new CX430 V2 stacks up against the original CX430.

The CX series, also known as the Builder series, is the most entry-level power supply series from Corsair, with 400 W, 430 W, 500 W and 600 W models. The 400 W model has been discontinued by the manufacturer, and all other models were recently updated to include the 80 Plus standard certification and extended warranty. These updated models have a “V2” after their names.

It is important to understand that while the CX400W was manufactured by Seasonic, all the other models are manufactured by CWT.

The Corsair CX430 V2 is internally identical to the original CX430, with the exception of the active PFC transistors and +12 V rectifiers, which were upgraded.

Look at Figures 1 and 2, and notice how the “V2” is not written after “CX430” on the labels available on the sides of the product, but in very small letters on the main power supply label. So, you must pay close attention to look for and buy the correct unit.

Figure 1: Corsair CX430 V2 power supply

Figure 2: Corsair CX430 V2 power supply

The Corsair CX430 V2 is 5.5” (140 mm) deep, using a 120 mm sleeve bearing fan on its bottom (Yate Loon D12SH-12, maximum of 3,000 rpm, and 101 cfm).

This unit features active PFC, of course, and doesn’t come with a modular cabling system. The cables are protected with nylon sleeves, and the unit comes with the following cables and connectors:

• Main motherboard cable with a 20/24-pin connector, 24.4” (62 cm) long
• One cable with two ATX12V connectors that together form an EPS12V connector, 24.4” (62 cm) long
• One cable with one six/eight-pin connector for video cards, 23.6” (60 cm) long
• Two cables, each with two SATA power connectors, 16.5” (42 cm) to the first connector, 5.9” (15 cm) between connectors
• One cable with three standard peripheral power connectors and one floppy disk drive power connector, 16.5” (42 cm) to the first connector, 5.9” (15 cm) between connectors

All wires are 18 AWG, which is the minimum required gauge.

The cable configuration is compatible with an entry-level 430 W product, with only one video card power connector and a reduced number of SATA and peripheral power connectors. This is the same configuration as the original CX430.

Figure 3: Cables

Let’s now take an in-depth look inside this power supply.

[nextpage title=”A Look Inside the Corsair CX430 V2″]

We decided to disassemble this power supply to see what it looks like inside, how it is designed, and what components are used. Please read our Anatomy of Switching Power Supplies tutorial to understand how a power supply works and to compare this power supply to others.

On this page we will have an overall look, and then in the following pages we will discuss in detail the quality and ratings of the components used. As mentioned, internally this unit is identical to the original Corsair CX430, with the exception of the active PFC transistors and +12 V rectifiers, which were upgraded.

Figure 4: Top view

Figure 5: Front quarter view

Figure 6: Rear quarter view

Figure 7: The printed circuit board

[nextpage title=”Transient Filtering Stage”]

As we have mentioned in other articles and reviews, the first place we look when opening a power supply for a hint about its quality, is its filtering stage. The recommended components for this stage are two ferrite coils, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor), and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components, usually removing the MOV and the first coil. 

In this power supply, this stage is flawless. It has one X capacitor and two Y capacitors more than the minimum required.

Figure 8: Transient filtering stage (part 1)

Figure 9: Transient filtering stage (part 2)

Now let’s have a more detailed discussion of the components used in the Corsair CX430 V2.

[nextpage title=”Primary Analysis”]

On this page we will take an in-depth look at the primary stage of the Corsair CX430 V2. For a better understanding, please read our Anatomy of Switching Power Supplies
tutorial.

This power supply uses one GBU806 rectifying bridge on its primary, which, unfortunately, isn’t attached to a heatsink. This component supports up to 8 A at 100° C (if a heatsink is used; the manufacturer doesn’t say how much current this bridge supports when not attached to a heatsink), so in theory, you would be able to pull up to 920 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 736 W without burning itself out. Of course, we are only talking about this component, and the real limit will depend on all the other components in this power supply.

Figure 10: Rectifying bridge

The active PFC circuit uses two MDF18N50 MOSFETs, each one supporting up to 18 A at 25° C or 11 A at 100° C in continuous mode (note the difference temperature makes), or up to 72 A at 25° C in pulse mode. This transistor presents a 270 mΩ resistance when turned on, a characteristic called RDS(on). The lower this number the better, meaning that the transistor will waste less power, and the power supply will have a higher efficiency. The original CX430 uses different transistors here (STP14NK50ZFP), with lower current limits and higher RDS(on).

Figure 11: Active PFC transistors and diode

The electrolytic capacitor that filters the output of the active PFC circuit is from Samxon and labeled at 85° C.

In the switching section, two AOTF10N60 power MOSFETs are used in the traditional two-transistor forward configuration. Each one supports up to 10 A at 25° C or 7.2 A at 100° C in continuous mode, or up to 36 A at 25° C in pulse mode, with an RDS(on) of 750 mΩ, which is very high.

Figure 12: Switching transistors

The primary is controlled by the omnipresent CM6800 active PFC/PWM combo.

Figure 13: Active PFC/PWM combo controller

Let’s now take a look at the secondary of this power supply.

[nextpage title=”Secondary Analysis”]

The Corsair CX430 V2 has four Schottky rectifiers attached to its secondary heatsink.

The maximum theoretical current each line can deliver is given by the formula I / (1 – D) where D is the duty cycle used and I is the maximum current supported by the rectifying diode. As an exercise, we can assume a duty cycle of 30 percent.

The +12 V output uses two SBR40U60CT Schottky rectifiers (40 A, 20 A per internal diode at 125° C, 0.60 V maximum voltage drop), giving us a maximum theoretical current of 57 A or 686 W for this output. These rectifiers are more powerful than the ones used in the original CX430 (MBR3045CTP, 30 A, 15 A per internal diode at 125° C, 0.65 V maximum voltage drop).

The +5 V output uses one MBR2545CTG Schottky rectifier (30 A, 15 A per internal diode at 160° C, 0.82 V maximum voltage drop), giving us a maximum theoretical current of 21 A or 107 W for the +5 V output.

The +3.3 V output uses another MBR2545CTG Schottky rectifier, giving us a maximum theoretical current of 21 A or 71 W for the +3.3 V output.

All these numbers are theoretical. The real amount of current/power each output can deliver is limited by other components, especially by the coils used on each output.

Figure 14: The +5 V and the two +12 V rectifiers

Figure 15: The +3.3 V rectifier

This power supply uses an ST9S429 monitoring integrated circuit, which apparently is a rebranded S3515. This chip supports over voltage (OVP), under voltage (UDP), and over current (OCP) protections. There are two +12 V OCP channels, but the manufacturer decided to use only of them, making this unit a single-rail model.

Figure 16: Monitoring circuit

The electrolytic capacitors available in the secondary are from Teapo and Samxon and labeled at 105° C.

[nextpage title=”Power Distribution”]

In Figure 17, you can see the power supply label containing all the power specs.

Figure 17: Power supply label

This power supply has a single +12 V rail, so there is not much to talk about here.

Let’s now see if this power supply can really deliver 430 W.

[nextpage title=”Load Tests”]

We conducted several tests with this power supply, as described in the article Hardware Secrets Power Supply Test Methodology.  

First, we tested this power supply with five different load patterns, trying to pull around 20%, 40%, 60%, 80% and 100% of its labeled maximum capacity (actual percentage used listed under “% Max Load”), watching the behavior of the reviewed unit under each load. In the table below, we list the load patterns we used and the results for each load.

If you add all the powers listed for each test, you may find a different value than what is posted u
nder “Total” below. Since each output can have a slight variation (e.g., the +5 V output working at +5.10 V), the actual total amount of power being delivered is slightly different than the calculated value. In the “Total” row, we are using the real amount of power being delivered, as measured by our load tester.

The +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During this test, both were connected to the power supply single +12 V rail (the EPS12V connector was installed on the +12VB input).

Input	Test 1	Test 2	Test 3	Test 4	Test 5
+12VA	3 A (36 W)	6 A (72 W)	9 A (108 W)	12 A (144 W)	15 A (180 W)
+12VB	3 A (36 W)	6 A (72 W)	9 A (108 W)	12 A (144 W)	15 A (180 W)
+5 V	1 A (5 W)	2 A (10 W)	4 A (20 W)	5 A (25 W)	7 A (35 W)
+3.3 V	1 A (3.3 W)	2 A (6.6 W)	4 A (13.2 W)	5 A (16.5 W)	7 A (23.1 W)
+5VSB	1 A (5 W)	1 A (5 W)	1 A (5 W)	1.5 A (7.5 W)	2 A (10 W)
-12 V	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)
Total	90.6 W	170.1 W	258.0 W	338.6 W	428.4 W
% Max Load	21.1%	39.6%	60.0%	78.7%	99.6%
Room Temp.	45.0° C	44.4° C	44.2° C	44.5° C	46.1° C
PSU Temp.	48.1° C	48.2° C	48.1° C	48.2° C	48.7° C
Voltage Stability	Pass	Pass	Pass	Pass	Pass
Ripple and Noise	Pass	Pass	Pass	Pass	Pass
AC Power	109.1 W	199.1 W	304.8 W	406.6 W	527.7 W
Efficiency	83.0%	85.4%	84.6%	83.3%	81.2%
AC Voltage	116.1 V	115.4 V	114.3 V	113.3 V	112.3 V
Power Factor	0.969	0.986	0.99	0.994	0.995
Final Result	Pass	Pass	Pass	Pass	Pass

The Corsair CX430 V2 can really deliver its labeled wattage at high temperatures.

Efficiency was between 81.2% and 85.4%, which is outstanding for a USD 45 power supply. In fact, these numbers are comparable to several 80 Plus Bronze units we’ve reviewed.

Voltage regulation was very good, with all voltages within 3% of their nominal values, except the -12 V output during test one and the +5 V output during test five (+4.83 V), but they were still inside the proper range. This means that voltages were closer to their nominal values than required by the ATX12V specification most of the time. The ATX12V specification says positive voltages must be within 5% of their nominal values and negative voltages must be within 10% of their nominal values. This tighter regulation is rarely seen on an entry-level power supply.

Noise and ripple levels were always extremely low. Below you can see the results for the power supply outputs during test number five. The maximum allowed is 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V, +3.3 V and +5VSB outputs. All values are peak-to-peak figures.

Figure 18: +12VA input from load tester during test five at 428.4 W (22.4 mV)

Figure 19: +12VB input from load tester during test five at 428.4 W (20.6 mV)

Figure 20: +5 V rail during test five at 428.4 W (17.4 mV)

Figure 21: +3.3 V rail during test five at 428.4 W (19.4 mV)

Let’s see if we can pull more than 430 W from this unit.

[nextpage title=”Overload Tests”]

Below you can see the maximum we could pull from this power supply. If we tried to pull more than that the unit shut down, showing that its protections were working well. During this test noise levels were still below the maximum allowed. We could pull a little bit more with the original CX430 (548.8 W).

Input	Overload Test
+12VA	18 A (216 W)
+12VB	18 A (216 W)
+5 V	10 A (50 W)
+3.3 V	10 A (33 W)
+5VSB	2 A (10 W)
-12 V	0.5 A (6 W)
Total	517.4 W
% Max Load	120.0%
Room Temp.	44.4° C
PSU Temp.	48.6° C
AC Power	671 W
Efficiency	77.1%
AC Voltage	109.6 V
Power Factor	0.997

[nextpage title=”Main Specifications”]

The specifications for the Corsair CX430 V2 power supply include:

• Standards: ATX12V 2.3
• Nominal labeled power: 430 W at 30° C
• Measured maximum power: 517.4 W at 44.4° C ambient
• Labeled efficiency: 80% minimum, 80 Plus standard certification
• Measured efficiency: Between 81.2% and 85.4% at 115 V (nominal, see complete results for actual voltage)
• Active PFC: Yes
• Modular Cabling System: No
• Motherboard Power Connectors: One 20/24-pin connector and two ATX12 V connectors that together form an EPS12V connector
• Video Card Power Connectors: One six-pin
• SATA Power Connectors: Four on two cables
• Peripheral Power Connectors: Three on one cable
• Floppy Disk Drive Power Connectors: One
• Protections (as listed by the manufacturer): Over voltage (OVP), under voltage (UVP), over power (OPP), short-circuit (SCP)
• Are the above protections really available: Yes. Over current protection (OCP) is present.
• Warranty: Three years
• Real Manufacturer: CWT
• More Information: https://www.corsair.com
• Average price in the US*: USD 45 (USD 35 after a mail-in rebate card)

* Researched at Newegg.com on the day we published this review.

[nextpage
title=”Conclusions”]

The Corsair CX430 V2 proved to be an outstanding product, possibly the power supply with the best cost/benefit ratio we’ve ever seen. Costing only USD 45 (USD 35 after sending a mail-in rebate card), it provides efficiency between 81.2% and 85.4%, which is comparable to several 80 Plus Bronze units we’ve reviewed. It also has a very good voltage regulation and ultra-low noise and ripple levels. The cable configuration is compatible with an entry-level 430 W unit, and users that need more cables will have to buy a different product.

The only differences between the CX430 V2 and the original CX430 are the active PFC transistors and the +12 V rectifiers, which were upgraded. These changes improved efficiency considerably. (The original CX430 presented efficiency between 79.4% and 84.1%.)

It is impossible to not get excited with a product that is inexpensive and provides the same performance level of more expensive units.