Corsair CX650M PSU Review

A Look Inside And Component Analysis

Parts Description

Before proceeding with this page, we strongly encourage you to 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. Our main tools for disassembling PSUs are a Thermaltronics soldering and rework station, and a Hakko FR-300 desoldering gun.

General Data
Manufacturer (OEM)CWT
Platform Model-
Primary Side
Transient Filter4x Y caps, 2x X caps, 2x CM & 1x DM chokes, 1x MOV
Inrush ProtectionNTC Thermistor & Diode
Bridge Rectifier(s)1x GBU1006 (600 V, 10 A @ 100 °C)
APFC MOSFETs2x Fairchild FCPF190N60E (650 V, 13.1 A @ 100 °C, 0.16 Ω)
APFC Boost Diode1x STMicroelectronics STTH8S06D (600 V, 8 A @ 125 °C)
Hold-up Cap(s)1x Nippon Chemi-Con (400 V, 470 uF, 2000h @ 105 °C, KMW)
Main Switchers2x Infineon IPA50R280CE (550 V, 11.4 A @ 100 °C, 0.28 Ω)
Combo APFC/PWM ControllerChampion CM6800TX
TopologyPrimary side: Double-Forward
Secondary side: Synchronous Rectification & DC-DC converters
Secondary Side
+12V MOSFETs4x Infineon BSC039N06NS (60 V, 65 A @ 100 °C, 3.9 mΩ)
5V & 3.3VDC-DC Converters: 3x UBIQ QM3006D (30 V, 57 A @ 100 °C, 5.5 mΩ), 3x UBIQ QM3004D (30 V, 40 A @ 100 °C, 8.5 mΩ)
PWM Controller: ANPEC APW7159
Filtering CapacitorsElectrolytics: Nippon Chemi-Con (105 °C, KY), SAMXON (105 °C), Su'scon (105 °C)
Polymers: Nippon Chemi-Con, APAQ, Teapo
Supervisor ICWeltrend WT7502 (PG, OVP, UVP, OCP, SCP)
Fan ModelHong Hua HA1225H12S-Z (120 mm, 12 V, 0.58 A, 2200 RPM, sleeve bearing)
5VSB Circuit
Rectifier1x MBR2045CT SBR (45 V, 20 A)

Standby PWM Controller

On-Bright OB5269CP

All CX units are made by CWT, and this one is based on a custom platform that's used exclusively by Corsair. The design is pretty good for a mainstream PSU with Bronze-class efficiency. Besides a synchronous design, where FETS regulate the +12V rail, a couple of voltage regulation modules handle the minor rails on the secondary side. In addition, the transient/EMI filter looks complete, and the bulk cap is provided by a respected Japanese manufacturer.

The first part of the EMI filter starts at the AC receptacle with a couple of Y caps. It continues as usual on the main PCB with two more Y caps, two X ones, two CM chokes, a single DM choke, and an MOV hidden well under a mountain of glue.

The single bridge rectifier is bolted on a dedicated heat sink. It is a GBU1006, which can handle up to 10 A of current, so it meets this unit's demands.

The APFC converter uses a couple of Fairchild FCPF190N60E and a single STMicroelectronics STTH8S06D boost diode. The smoothing (bulk) cap is provided by Chemi-Con (400 V, 470 uF, 2000h @ 105 °C, KMW). Although its capacity looks pretty low, it provides a long enough hold-up time to meet the ATX spec's requirements. Our only complaint is the low voltage rating, which comes close to the APFC's DC bus voltage (around 380 VDC).

An NTC thermistor protects against large inrush currents. A diode is installed before the thermistor, reducing power losses. Of course, a thermistor is essentially a resistor with temperature-dependent resistance. The higher its temperature, the lower its resistance, meaning that once it gets hot, energy losses on it are dramatically reduced.

The combo PFC/PWM controller is a Champion CM6800TX, which is widely used in 80 PLUS Bronze PSUs. It is soldered to PCB's business side. Close to it we see the supervisor IC, a Weltrend WT7502 that only enables the absolute necessary protection features.

The primary FETs are two Infineon IPA50R280CEs, arranged into a double-forward topology.

We had to remove the main transformer to identify major parts like the primary FETs, along with components used by the +12V regulation circuit.

On the secondary side, a small daughterboard houses four Infineon BSC039N06NS FETs, responsible for regulating the +12V rail. The cooling of those FETs is handled by a number of bus bars and not by heat sinks. CWT uses this cooling method liberally in its recent implementations, and it appears to work well.

The electrolytic filtering caps are provided mostly by Samxon and Su'scon, while we also find a Chemi-Con KY cap that's likely used by the 5VSB rail. Besides electrolytic caps, CWT utilizes polymer ones sourced from Apaq and Teapo as well. There is even a single Chemi-Con polymer cap installed on the main PCB. It is always nice to see polymer caps used in mainstream PSUs, since they have a much longer lifetime and aren't affected by high operating temperatures as much as electrolytic ones.

This board houses both VRMs that generate the minor rails. Three UBIQ QM3006D FETs are used by the 5V rail and three UBIQ QM3004D handle the 3.3V rail. The common PWM controller is a Anpec APW7159. Two not-so-nice-looking Teapo polymer caps are installed on the front side of the VRM board.

The 5VSB rail is regulated by a MBR2045CT SBR, while the standby PWM controller is a On-Bright OB5269CP. The latter is installed on the solder side of the PCB.

We find several Apaq polymer caps on the front side of the modular board; they're used for ripple filtering purposes.

The soldering quality is quite good for this price segment.

The fan is made by Hong Hua and its model number is HA1225H12S-Z (120 mm, 12 V, 0.58 A, 2200 RPM, sleeve bearing). This is a capable cooler able to spin as fast as 2200 RPM. Fortunately, Corsair's fan profile is fairly relaxed, so under normal operating conditions the CX650M will be fairly quiet. It'd be ideal, however, if the minimum fan speed was lower than 840 RPM.

This thread is closed for comments
44 comments
    Your comment
  • Dark Lord of Tech
    Thanks for the review on this new CXM platform.
  • JQB45
    Looks to be better then the old CX line up.
  • Onus
    Good to see that Corsair didn't produce a[nother] Turkey with this one.
  • turkey3_scratch
    Onus why would Corsair produce me?

    Anyway I think the price/performance page shows all. This thing rocks!

    Also Jonnyguru claims it is a rifle bearing fan that has the same model # as the sleeve variant.
  • benedict78
    Does the CX650 perform the same as the CX650M? I'm not interested in modularity anyway.
  • turkey3_scratch
    The CX650 is not out yet.
  • Aris_Mp
    I have several CM and CX-M units, which I plan to fully evaluate. So far I figured that there are differences (something natural of course) in their performance.
  • Dark Lord of Tech
    Could you put the newer CXM 750W OR 850W on deck soon , as they are widely use for DUAL CARD configurations.
  • turkey3_scratch
    The 750W and 850W CXM units are basically unchanged except for a bridge rectifier upgrade. Everything else is the same. Only the CX450-650M got the major revisions.
  • Dark Lord of Tech
    Yeah I know that , but want to see one reviewed , to compare top older generations.
  • Ryan_78
    Seems cool to be a CX now. Nice
  • bettsar
    After getting such high marks from the review, why no award?
  • Aris_Mp
    The CX750M is on the test bench right now. I don't have a CX850M sample.
  • Aris_Mp
    About the award. It should have a recommendation award but as it seems we forgot to add it. On it right now :)
  • Math Geek
    good to see them making a strong performer in a moderate price range. if they drop some massive rebates over the holidays like they do most years, this will be a super buy. i'm keeping my eye out to stock up on some. looks like a very solid buy.
  • atljsf
    the modularity is nice if you have a mini itx case, i have a cx500 and some of the unused cables are a bit inconvenient so that cx650m should be nice for those with not that small mini itx cases that can fit normal size psus
  • HERETIC-1
    Corsair spend $3 more and get all Jap capacitors and you'll have a good PSU.
    Oh you have-It's called the Vengeance series.(RECOMMENDED)
  • turkey3_scratch
    HERETIC you are severely misled. Do you realize there are Chinese capacitors of higher quality than Japanese? Do you realize how much ripple a capacitors handles and the environment the capacitors is in also affects it's lifespan a lot?

    Look at the thermal shots. The PSU is significantly cooler than was expected. That is fantastic for capacitor life. If you want to persist at judging power supplies based on capacitors country (and BTW a lot of Jap caps are outsourced to China) then you will be misled.
  • HERETIC-1
    So turkey are you saying Corsair's marketing "105C JAPANESE CAPACITORS"
    on their vengeance series is not necessary?
    I am more than happy to pay a little more when I see-
    "All electrolytic caps come from Nippon Chemi-Con"
  • turkey3_scratch
    The Vengeance series is a higher end unit than the CXM at a different price category for different countries. Not really fair to compare them.

    What more.could you possibly want at the price this thing sells for? This is the best value period and you have to find the need to talk about Japanese caps without even knowing the spec sheets of these caps used.
  • 10tacle
    "Finally, the number of provided cables and connectors is sufficient for this unit's capacity. And although it isn't fully modular, the native cables are absolutely necessary anyway."

    I've never understood the logic behind a "fully" modular PSU where all cables are completely disconnected and need to be plugged in. How exactly are you not going to use a PSU in a PC without the 20+4 pin ATX and 8 pin 12v CPU power connectors going to the motherboard?

    If anything, I'd want those connected directly during manufacturing to ensure nothing is lost (output or resistance) through a transfer connector port to the two most crucial power connectors.
  • atljsf
    202972 said:
    "Finally, the number of provided cables and connectors is sufficient for this unit's capacity. And although it isn't fully modular, the native cables are absolutely necessary anyway." I've never understood the logic behind a "fully" modular PSU where all cables are completely disconnected and need to be plugged in. How exactly are you not going to use a PSU in a PC without the 20+4 pin ATX and 8 pin 12v CPU power connectors going to the motherboard? If anything, I'd want those connected directly during manufacturing to ensure nothing is lost (output or resistance) through a transfer connector port to the two most crucial power connectors.


    the idea is that if you want a longer, half meter or a shorter, 15 centimeters long cable, you can change the one that came with the psu and put the one you need

    this is what most pc builders need this days, especially with mini itx cases where space is extremely limited
  • JQB45
    2011305 said:
    the idea is that if you want a longer, half meter or a shorter, 15 centimeters long cable, you can change the one that came with the psu and put the one you need this is what most pc builders need this days, especially with mini itx cases where space is extremely limited


    So If I buy power supply "A" for my mITX build and its fully modular but the cables are to long, where do I go to get shorter cables?
  • turkey3_scratch
    Cables cost like $100.