Corsair TX550M Power Supply Review

The TX550M is another good PSU by Corsair.

Corsair TX550M
(Image: © Tom's Hardware)

Tom's Hardware Verdict

The Corsair TX550M achieves high enough performance, and it has a silent operation under normal operating conditions.

Pros

  • +

    Full power at 47 degrees Celsius

  • +

    Good build quality

  • +

    Quiet and compact

  • +

    Within 1% load regulation on all rails

  • +

    Efficient

  • +

    Highly efficient 5VSB rail

  • +

    Long-enough hold-up time

  • +

    Low EMI emissions

  • +

    Compatible with alternative low power modes

  • +

    Low leakage current

  • +

    Two EPS and two PCIe connectors

  • +

    7-year warranty

Cons

  • -

    Transient response needs improvement (especially at 3.3V)

  • -

    Not fully modular

  • -

    High inrush current with 230V input

  • -

    Only three SATA connectors

  • -

    Small distance between SATA and 4-pin Molex connectors

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The Corsair TX550M is at a lower level in Corsair's portfolio than the RM550x, so naturally, it has to have a lower overall performance, not to create any problems for the latter. Still, it achieves high enough performance, and it isn't noisy, even under harsh conditions. If you don't have a problem with its semi-modular cable design and find it at a reasonable price, go for it. Units like the RM550x and the be quiet! Pure Power FM 11 keep the TX550M out of our best power supplies

We have already reviewed the 650W and 750W members of Corsair's TX-M line, so we thought to also put the smallest member, with 550W, to the test. Thanks to the limited depth of 140mmn, all TX-M models have compact dimensions and use a semi-modular cable design. They are rated as Gold by 80 PLUS and Cybenetics, and the TX550M has a Cybenetics A (20-25 dB[A]) noise rating. Lastly, the OEM behind these units is Great Wall, which also provides Corsair's SF models. 

The TX550M comes with a 120mm fan, which uses a rifle bearing. This is not the best bearing type. Still, it is way better than a plain sleeve bearing, and it doesn't cost as much as a fluid dynamic bearing. Although the PSU uses a modern platform, it cannot deliver full load at 12V, on paper at least, which is weird. All PSUs featuring DC-DC converters should not have a problem delivering full load at 12V with a minor load on the minor rails since, in essence, the rail providing power to the minor rails is the 12V one. 

Specifications: Corsair TX550M

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Manufacturer (OEM)Great Wall
Max. DC Output550W
Efficiency80 PLUS Gold, Cybenetics Gold (87-89%)
NoiseCybenetics A (20-25 dB[A])
Modular✓ (semi)
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
Cooling120mm Rifle Bearing Fan (NR120L)
Semi-Passive Operation
Dimensions (W x H x D)150 x 85 x 140mm
Weight1.54 kg (3.4 lb)
Form FactorATX12V v2.52, EPS 2.92
Warranty7 Years

Power Specifications: Corsair TX550M

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RailRow 0 - Cell 1 3.3V5V12V5VSB-12V
Max. PowerAmps25204330.8
Row 2 - Cell 0 WattsRow 2 - Cell 2 120516159.6
Total Max. Power (W)Row 3 - Cell 1 Row 3 - Cell 2 550Row 3 - Cell 4 Row 3 - Cell 5 Row 3 - Cell 6

Cables & Connectors for Corsair TX550M

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DescriptionCable CountConnector Count (Total)GaugeIn Cable Caps
Native Cables    
ATX connector 20+4 pin (610mm)1118-20AWGNo
4+4 pin EPS12V (650mm)1118AWGNo
Modular CablesRow 3 - Cell 1 Row 3 - Cell 2 Row 3 - Cell 3 Row 3 - Cell 4
4+4 pin EPS12V (650mm)1118AWGNo
6+2 pin PCIe (600mm+150mm)1216-18AWGNo
SATA (500mm+95mm+95mm))1318AWGNo
4 pin Molex (450mm+100mm+100mm+100mm)1418AWGNo

The only fixed cables are the ATX and the first EPS, which are essential. The other cables are modular. It is nice to see two EPS connectors on a 550W unit, along with a pair of PCIe connectors, although the latter are on a single cable. 

This is the first time we see a PSU having more 4-pin Molex connectors than SATA ones. There should be more SATA connectors. On top of that, the distance between the peripheral connectors is too short at 95-100mm. 

Component Analysis of Corsair TX550M

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 TypeDouble Sided
Primary Side-
Transient Filter4x Y caps, 2x X caps, 3x CM chokes, 1x MOV
Inrush ProtectionNTC Thermistor SCK-2R58 (2.5Ohm) & Relay
Bridge Rectifier(s)1x GBU1508 (800V, 15A @ 100°C)
APFC MOSFETs 1x STMicroelectronics STW34NM60N (600V, 18A @ 100°C, Rds(on): 0.11Ohm)
APFC Boost Diode 1x CREE C3D04060A (600V, 4A @ 155°C)
Bulk Cap(s) 2x Rubycon (450V, 270uF each or 540uF combined, 3,000h @ 105°C, MXG)
Main Switchers 2x STMicroelectronics STF24N60DM2 (600V, 11A @ 100°C, Rds(on): 0.2Ohm)
APFC Controller Champion CM6500UNX & Champion CM03AX
Resonant ControllerChampion CU6901VPA
Topology Primary side: APFC, Half-Bridge & LLC converter Secondary side: Synchronous Rectification & DC-DC converters
Secondary Side-
+12V MOSFETs4x Advanced Power Electronics AP4N1R8CMT-A (45V, 180A, Rds(on): 1.8mOhm)
5V & 3.3VDC-DC Converters: 6x Advanced Power Electronics D508 PWM Controllers: ANPEC APW7159C
Filtering Capacitors

Electrolytic: 1x Rubycon (6-10,000h @ 105°C, ZLH), 5x Rubycon (4-10,000h @ 105°C, YXJ), 1x Rubycon (3-6,000h @ 105°C, YXG), 1x Nippon Chemi-Con (4-10,000h @ 105°C, KY) Polymer: 9x Nippon Chemi-Con, 4x FPCAP

Step-Down DC-DC ConverterTexas Instruments TPS54231
Supervisor ICIN1S429I-SCG (OVP, UVP, OCP, SG, PGO)
Fan ModelCorsair NR120L (120mm, 12V, 0.22A, Rifle Bearing Fan)
5VSB Circuit-
Rectifier 1x Diodes Incorporated SBR10E45P5 SBR (45V, 10A)
Standby PWM ControllerPower Integrations TNY278GN

Despite its small size, the PCB is not densely populated, allowing good airflow between parts. The platform is provided by Great Wall, the same OEM that builds Corsair's SFX units (SF series). All parts are of high quality, and the fixed wires are installed in such a way to block as less as possible the airflow on the secondary side. On the primary side, we find a half-bridge topology and an LLC resonant converter, while on the secondary side, a synchronous design is used along with DC-DC converters for the minor rails. 

The transient/EMI filter has all necessary parts, with an additional CM choke, and it does a good job in suppressing incoming and outgoing EMI emissions. There is also an MOV and an NTC thermistor supported by a bypass relay, for protecting against voltage surges and large inrush currents. 

Corsair TX550M

(Image credit: Tom's Hardware)

The single bridge rectifier can handle up to 15A A of current at 100 degrees Celsius, so it will easily cover this PSU's needs. 

The APFC converter uses two FETs, provided by STMicroelectronics, and a single CREE diode. The bulk caps are of high quality since they are provided by Rubycon, while the APFC controller is a Champion CM6500, supported by a CM03AX. 

The main FETs are by STMicroelectronics and are installed into a half-bridge topology. There is also an LLC resonant converter to boost efficiency. The resonant controller is a Champion CM6901. 

Four FETs are used by the 12V rail. There is room for two more for higher power output. A small heat sink on the business side of the PCB helps them cool down. A pair of DC-DC converters regulate the minor rails. 

The few electrolytic caps are of high quality. Like the electrolytic ones, all the polymer caps are made by Japanese manufacturers. 

The standby PWM controller is a Power Integrations TNY278GN IC. 

Corsair TX550M

(Image credit: Tom's Hardware)

The small modular board hosts four polymer caps. There is space available for four more, and two additional sockets. 

Corsair TX550M

(Image credit: Tom's Hardware)

The main supervisor IC is an IN1S429I-SCG, which is semi-hidden by the polymer caps of the DC-DC converters. 

Soldering quality is good, although there is not much to see on this side of the PCB. 

The NR120L fan uses a rifle bearing, so it will last for long. This is a low speed fan, so noise output will be reduced even under high operating temperatures and increased load levels. 

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Aris Mpitziopoulos
Contributing Editor

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