Corsair CX450M Review. A PSU that won’t break the bank!

The Corsair CX450M is a decent-performing PSU that won’t break the bank. Despite the semi-modular cable design, the CX450M is inferior to the CX450, which used a more advanced platform and, thus, more expensive. 

It is a shame that there aren’t many reviews of budget PSUs (and budget products in general). But I totally get it, brands don’t want to send their low-cost products for evaluation, especially to me. Only Corsair is brave enough to do it, and on top of that, they don’t complain about the review’s outcome, in most cases, at least!

Since I have already reviewed the CX650M at TechPowerUp, I thought to take a look at the smallest member of the CX-M line, with 450W max power. The new CX-M units come in four flavors, with their capacities ranging from 450W up to 750W. The previous line also had an 850W unit. All CX-M PSUs feature a semi-modular cable design and use a low-cost CWT platform to keep the price tags as low as possible. Someone would expect the CX-M models to perform better than the non-modular ones, but this is not the case since the latter use a highly capable and expensive platform. Because of the increased cost, Corsair had to terminate CX units in favor of the CX-M ones.

Cybenetics Report – CX450M Cybenetics Report – CX450 (CWT) Cybenetics Report – CX450 (Great Wall)

 

Technical Specifications:
  • Manufacturer (OEM): CWT
  • Max Power: 450W
  • Efficiency: Cybenetics Bronze (82-85%), 80 PLUS Bronze
  • Noise: Cybenetics Standard++ (30 – 35 dBA)
  • Compliance: ATX12V v2.4, EPS 2.92
  • Alternative Low Power Mode support: Yes
  • Power 12V: 448.8W
  • Power 5V + 3.3v: 110W
  • Power 5VSB: 15W
  • Cooling: 120 mm Rifle Bearing Fan (HA1225H12F-Z)
  • Semi-Passive Operation: No
  • Modular Design: Yes (semi)
  • High Power Connectors: 1x EPS, 2x PCIe 6+2 pin (single cable)
  • Peripheral Connectors: 4x SATA (single cable), 3x 4-pin Molex (single cable)
  • ATX/EPS Cable Length: 600/660mm
  • Distance between SATA connectors: 110mm
  • Distance between 4-pin Molex connectors: 100mm
  • Dimensions (W x H x D): 150 mm x 85 mm x 140 mm
  • Weight: 1.54 kg (3.40 lb)
  • Warranty: 5 years

Box & Bundle

The box has small dimensions, and on its face is a photo of the product with the new fan grille in view. Thanks to the different exterior design, it will be easy to spot the new CX-M units from the old ones. Inside the box, a bubble wrap protects the PSU, and the bundle includes the basics and a set of zip ties.

Protection Features

OCP +12 V: 45.2 A (120.86%), 11.988 V
+5 V: 29.5 A (147.5%), 5.042 V
+3.3 V: 27.7 A (138.5%), 3.315 V
5 VSB: 4.2 A (140%), 5.008 V
OPP 571.14 W (126.92%)
OTP Yes (124 °C @ +12 V Heat Sink)
SCP 12V to Earth: ✓
5V to Earth: ✓
3.3V to Earth: ✓
5VSB to Earth: ✓
-12V to Earth: ✓
PWR_OK Accurate but lower than 16 ms
NLO
SIP Surge: MOV
Inrush: NTC Thermistor

OCP is properly set at 12V, and the same goes for OPP. On the contrary, OCP is set high on the minor rails. The rest protection features are present and working ok.

Part Analysis

General Data
Manufacturer (OEM) CWT
PCB Type Single Sided
Primary Side
Transient Filter 4x Y caps, 2x X caps, 2x CM chokes, 1x MOV, 1x CAP200DG (Discharge IC)
Inrush Protection NTC Thermistor SCK – 2R58 (2.5Ohm)
Bridge Rectifier(s)
1x GBU808 (800V, 8A @ 100°C)
APFC MOSFETs
2x Silan Microelectronics SVF18N50F (500V, 11A @ 100°C, Rds(on): 0.31Ohm)
APFC Boost Diode
1x STMicroelectronics STTH8S06D (600V, 8A)
Bulk Cap(s)
1x Nippon Chemi-Con (400V, 220uF, 2,000h @ 105°C, KMR)
Main Switchers
2x Silan Microelectronics SVF13N50F (500V, 8.2A @ 100°C, Rds(on): 0.52Ohm)
PFC/PWM Combo Controller Champion CM6800TX & Champion CM03X
Topology
Primary
side: APFC, Double Forward
Secondary side: Passive Rectification (12V)  & DC-DC converters (5V & 3.3V)
Secondary Side
+12V SBRs 2x Silan Microelectronics SBD20C60T (60V, 20A) & 2x PFC PFR20L60CT (60V, 20A)
5V & 3.3V MOSFETs 2x UBIQ QM3054M6 (30V, 61A @ 100°C, Rds(on): 4.8mOhm) & 2x UBIQ QN3107M6N (30V, 70A @ 100°C, Rds(on): 2.6mOhm)
PWM Controller: ANPEC APW7159C
Filtering Capacitors Electrolytic: 6x Elite (2-5,000h @ 105°C, ED), 2x Nippon Chemi-Con (4-10,000h @ 105°C, KY), 1x Nippon Chemi-Con (1-5,000h @ 105°C, KZE), 6x Elite (4-10,000h @ 105°C, EY), 2x Elite (2,000h @ 105°C, PF)
Polymer: 9x APAQ
Supervisor IC INI1S429I – DCG
Fan Model Hong Hua HA1225H12F-Z (120mm, 12V, 0.58A, Rifle Bearing Fan)
5VSB Circuit
Standby PWM Controller Power Integrations TNY290PG

The platform is provided by Channel Well Technology (CWT) and uses a single-sided PCB and an outdated design to lower the production cost. The FETs used don’t belong to a high-end manufacturer, but the capacitor choice is good. On the primary side, we find Chemi-Con bulk caps; on the secondary side, CWT used a mix of Elite and Chemi-Con electrolytic caps along with nine polymer ones. Moving to the cooling fan, one of the most important parts of a product, it is by Hong Hua. It uses a rifle bearing, so it will have a long life if you don’t push it under extremely high operating temperatures for prolonged periods. All in all, the parts Corsair asked from CWT to use are of decent quality, especially for a PSU of this price tag. If you need higher quality parts, and a more advanced platform, you will have to pay way more and get a real “Gold” efficiency unit.

Load Regulation

The only rail with below 1% deviation is the 5V one. 12V and 3.3V are within 2% and the 5VSB rail within 3%.

Ripple Suppression

Ripple is low on all rails.

Transient Response

I didn’t expect to see such a good transient response in this unit! The CX450M is the transient response performance king of the budget, low-capacity PSU category!

Hold Up Time

The hold-up time is ridiculously short because bulk caps are expensive. I would like to see above 12ms, at least.

Timings

The PSU supports Alternative Low Power Modes!

Inrush Current

Inrush current is low with 115V but pretty high with 230V.

Efficiency Normal, Light & Super-Light Loads

The platform achieves decent efficiency in all load ranges. Even with a 2% load, it is close to the 60% efficiency level that the ATX spec requires.

Average Efficiency 5VSB

The 5VSB rail is efficient.

Vampire Power

Vampire power is low.

Average Efficiency

The average efficiency is high enough for a Bronze PSU, featuring an older platform.

Average PF

The APFC converter does a good job.

Average Noise

There are other budget PSUs with a much lower average noise output, but you should also consider that this platform is not super efficient, so the thermal load that the fan has to face can be significant under harsh conditions.

Fan Noise & Speed Maps @ 28-32 °C

With up to 230W load, noise is below 20 dBA. Nonetheless, with 30W more, the 30 dBA mark is passed, and with 290W, you enter the 35-40 dBA zone.

Overall Performance

The CX450M registers lower performance than both CX450 versions, but this was expected given the more modern platform that the latter use. Nonetheless, the CX450M’s overall performance is decent, but it faces strong competition from the Thermaltake Smart BM2 and XPG Pylon units with similar capacity. The be quiet! SU9-500 is a top performer, as you can see, so if you find one, don’t hesitate to buy it!

Epilogue

Most people want to see budget-oriented product reviews, and I plan on doing this on this site. The major obstacle is the unwillingness of most brands to send low-end or even mid-end products for review, but I have my ways to find them. One of the very few brands that don’t have a problem sending low-cost units for review is Corsair, and why not from the moment the CX450M that I evaluated performed well? In areas that matter the most, like ripple suppression and transient response, the CX450M achieved high performance, and on top of that, its build quality is high enough to allow it to outlive the five-year warranty. What more should you expect from a 50-dollar PSU? I would say to find it at that price because, at the time of the review, it wasn’t available on Amazon, and its price was above 60 dollars on Newegg.

Other good alternative options are the XPG Pylon 450 and the Thermaltake Smart BM2 450, which use the same platform as the CX450M, CWT’s CSB-A. If you live in Europe, you should also consider the be quiet! SU9-500. As for the CX450 units, they are slowly disappearing from the market, but until that happens, they are included in my Best PSU Picks article.

Buy CX450M Buy XPG Pylon 450 Buy Thermaltake Smart BM2 Buy be quiet! SU9-500

 

Pros:
  • Full power at 47°C
  • Affordable
  • Efficient 5VSB rail
  • Good capacitors used
  • Not noisy under normal operating conditions
  • Top (for its category) transient response
  • Good ripple suppression
  • Accurate power ok signal
  • Over-temperature protection
  • Low inrush current with 115V input
  • Low vampire power
  • One EPS and two PCIe connectors
  • Rifle bearing fan
  • Semi-modular cable design
  • 5-year warranty
Cons:
  • Overall performance needs boosting to meet competing offerings
  • Short hold-up time
  • High OCP on the minor rails
  • High inrush current with 230V input
  • Short distance between all peripheral connectors

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