Corsair CX650 Power Supply Review

Capable for the mid-range

Corsair CX650 PSU
(Image: © Tom's Hardware)

Tom's Hardware Verdict

The Corsair CX650 is among the best 650W, budget-oriented PSUs you can find in today's market.

Pros

  • +

    Affordable

  • +

    Full power at 41 degrees Celsius

  • +

    High overall performance

  • +

    Tight load regulation

  • +

    Efficient

  • +

    Highly efficient 5VSB rail

  • +

    Low leakage current

  • +

    Low vampire power

  • +

    Long cables

Cons

  • -

    Very low hold-up time

  • -

    Transient response at +12V could be better

  • -

    Pretty high inrush current with 230V

  • -

    Non-modular cables

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    A second EPS or an ATX12V would be ideal

  • -

    Small distance between peripheral connectors

  • -

    The fan speed profile could be a bit less aggressive

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Corsair's CX line is made by two manufacturers, Channel Well Technology and Great Wall. Both are good OEMs with solid manufacturing lines. As we noticed in the CX450 review, both flavors have equal performance. In today's review, we will take a look at the Great Wall version of the CX650. You can distinguish it by its RPS number, which is RPS0065. RPS numbers are reference designators given to each Corsair model. The CWT-made CX650 has an RPS number of RPS0055.

The Corsair CX650 is among the best performing models in this budget category and a worthy competitor to some of the best power supplies. The CX650 achieves good efficiency levels, and load regulation is tight on all rails. The transient response could be better, though. The platform is modern, and according to Corsair's claims, it belongs to a higher efficiency level, but it is advertised at a lower level to keep both CWT and Great Wall versions of the CX650 on the same page. Worthy contenders in this category are the Cooler Master MWE Bronze 650, and 700 models and the similar capacity be quiet! System Power U9 model, if you can find it in the US market, where be quiet! doesn't have a significant presence.

According to Jon Gerow (aka Jonnyguru), the Great Wall version of the CX650 has higher efficiency than its CWT counterpart, 80 PLUS Silver. Still, it is advertised as Bronze to stay in the same category and not bring confusion to future buyers. For the standards of this mainstream category, the design is pretty good, since, besides DC-DC converters for the minor rails, an LLC resonant converter is also used on the primary side for higher efficiency. The temperature rating for continuous max power delivery is also high, at 40 degrees Celcius.

Specifications

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Manufacturer (OEM)

Great Wall

Max. DC Output

650W

Efficiency

80 PLUS Bronze, ETA-A- (85-88%)

Noise

LAMBDA-S++ (30-35 dB[A])

Modular

Intel C6/C7 Power State Support

Operating Temperature (Continuous Full Load)

0 - 40°C

Over Voltage Protection

Under Voltage Protection

Over Power Protection

Over Current (+12V) Protection

Over Temperature Protection

Short Circuit Protection

Surge Protection

Inrush Current Protection

Fan Failure Protection

No Load Operation

Cooling

120mm Rifle Bearing Fan (D12SM-12)

Semi-Passive Operation

Dimensions (W x H x D)

150 x 85 x 140mm

Weight

1.91 kg (4.21 lb)

Form Factor

ATX12V v2.4, EPS 2.92

Warranty

5 Years

Power Specifications

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Rail3.3V5V12V5VSB-12V
Max. PowerAmps25255430.8
Watts130648159.6
Total Max. Power (W)650

Cables and Connectors

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DescriptionCable CountConnector Count (Total)GaugeIn Cable Caps
ATX connector 20+4 pin (600mm)1118-20AWGNo
4+4 pin EPS12V (680mm)1118AWGNo
6+2 pin PCIe (600mm)2218AWGNo
SATA (520mm+120mm)1218AWGNo
SATA (400mm+120mm+120mm)1318AWGNo
4-pin Molex (400mm+120mm+120mm+120mm)1418AWGNo
AC Power Cord (1380mm) - C13 coupler1118AWG-

Cable length is satisfactory, but the distance between the peripheral connectors should be 150mm, at least. The number of SATA connectors could be larger, since one of the corresponding cables hosts only two of these connectors, while there are enough 4-pin Molex. With two PCIe, even high-end GPUs are supported, but this is not the case for the single EPS connector. Corsair could provide an additional EPS or an ATX12V 4-pin connector and retain compatibility with energy-hungry CPUs and the corresponding mainboards. 

Component Analysis

We strongly encourage you to have a look at our PSUs 101 article, which provides valuable information about PSUs and their operation, allowing you to better understand the components we're about to discuss.

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-General Data
Manufacturer (OEM)Great Wall
PCB TypeSingle Sided
-Primary Side
Transient Filter4x Y caps, 2x X caps, 2x CM chokes, 1x MOV
Inrush ProtectionNTC Thermistor SCK-028
Bridge Rectifier(s)2x Shindengen U15K80R (800V, 15A @ 101°C)
APFC MOSFETs2x Vishay SiHG30N60E (600V, 18A @ 100°C, Rds(on): 0.125Ohm)
APFC Boost Diode1x WeEn BYC15-600T (600V, 15A @ 98C)
Bulk Cap(s)2x Rubycon (450V, 180uF each or 360uF combined, 2,000h @ 105°C, MXH)
Main Switchers2x STMicroelectronics STP24N60DM2 (650V, 11A @ 100°C, Rds(on): 0.20Ohm)
APFC ControllerChampion CM6500UNX & CM03AX Green PFC controller
Resonant ControllerChampion CM6901X
TopologyPrimary side: APFC, Half-Bridge & LLC Resonant Converter Secondary side: Synchronous Rectification & DC-DC converters
-Secondary Side
+12V MOSFETs4x Advanced Power AP9990GPT (60V, 70A @ 100C, Rds(on): 6mOhm)
5V & 3.3VDC-DC Converters: 6x Advanced Power& AP0403GH (30V, 50A @ 100°C, Rds(on): 4.5mOhm) PWM Controllers: ANPEC APW7159C
Filtering CapacitorsElectrolytic: 2x Elite (2-5,000h @ 105°C, ED), 4x Elite (3-5,000h @ 105°C, EJ), 2x Elite (2-5,000h @ 105°C, EK), 1x Teapo (2-6,000h @ 105°C, SY), 1x Teapo (2,000h @ 105°C, TH), 2x Nippon Chemi-Con (4-10,000h @ 105°C, KY), 1x Rubycon (3-6,000h @ 105°C, YXG) Polymer: 4x Elite, 2x United Chemi-Con
Supervisor ICSitronix ST9S429-PG14 (OVP, UVP, OCP, SCP, PG)
Fan ModelYate Loon D12SM-12 (120mm, 12V, 0.30A, Rifle Bearing Fan)
-5VSB Circuit
Rectifier(s)1x A-Power AP04N60H-HF FET (600V, 2.2A @ 100°C, Rds(on): 2.5Ohm) & 1x PFC PFR20L45CT SBR (45V, 20A)
Standby PWM ControllerSI8016HSP8

This is the Great Wall version of the CX650, using a highly advanced, for the standards of this not so demanding category, platform. On the primary side, we find an LLC resonant converter and a half-bridge topology. A synchronous design handles +12V, and a pair of DC-DC converters generate the minor rails. The build quality is good, and GW used good parts, including Vishay and STMicroelectronics FETs, along with a rifle bearing fan. Finally, most of the electrolytic caps are provided by Elite, which is considered one of the best non-Japanese cap manufacturers.

The transient filter has all necessary parts, to effectively suppress EMI emissions, both incoming and outcoming. There is also an MOV, for protection against voltage surges, while an NTC thermistor lowers the inrush currents. It would be ideal, though, if there was a bypass relay and the thermistor's resistance should be higher, too. 

Two quality bridge rectifiers are used, able to handle up to 30 Amperes of current, so they are an overkill for a 650W power supply. 

The boost diode is quite strong for this platform. Usually, we find 6A to 8A boost diodes in 650W units, but the CX650 utilizes a 15A boost diode. While the boost diode is overrated, this is not the case for the bulk caps, which are of high quality but have low capacity.

The pair of STMicroelectronics FETs is arranged into a half-bridge topology, and an LLC resonant converter is also used to boost efficiency. This doesn't seem to be an ETA-S or 80 PLUS Bronze unit, but a higher efficiency rating one. 

Four Advanced Power FETs are installed on the secondary heat sink and handle the +12V rail. The minor rails are generated through two DC-DC converters.  

Most of the filtering caps are provided by Elite, which has a good reputation in the budget category segment. We also find several Chemi-Cons, Teapos, and a lonely Rubycon cap. The Japanese caps are installed in the 5VSB circuit, where top-quality components are required since this rail operates in passive mode with the PSU's fan, not in operation.

The 5VSB circuit uses an A-Power AP04N60H-HF FET on the primary side and a PFC PFR20L45CT SBR on its secondary side. Finally, the SI8016HSP8 takes over the role of the standby controller. 

The soldering quality is good.

We expected to find a Hong Hua fan, but Corsair gave a shot to Yate Loon and to its D12SM-12 fan that uses a rifle bearing. 

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Aris Mpitziopoulos
Contributing Editor

Aris Mpitziopoulos is a contributing editor at Tom's Hardware, covering PSUs.

  • mdd1963
    Lots of folks 'poo-poo' some of Corsair's PSU offerings, instead flocking to something w/Gold or Platinum in it'/s title, no matter the 150% price increase, and/or the 430W 'only' capacity...

    I've been happily using a Corsair 600 watt PSU (CX600) which cost me all of $55 or so in Feb 2017 if I recall correctly... ; never a stutter.
    Reply
  • grmaster
    any specific reason why this platform is so bad at advance transient response at 12v
    Reply