HX620W (also known as CMPSU-620HX) is a power supply that Corsair claims can deliver its rated power at 50° C, and featuring a modular cabling system, a big 120 mm fan, active PFC, high efficiency and two video card power cables for you to feed your SLI or CrossFire system. We completely disassembled this power supply to see the components and design used and also tested to see if it can really deliver its labeled 620 W.

Corsair HX620W Power SupplyFigure 1: Corsair HX620W.

Corsair HX620W Power SupplyFigure 2: Corsair HX620W.

HX620W features high-efficiency and active PFC. According to Corsair this power supply has an efficiency of at least 80% (compare to less than 70% on regular power supplies), meaning less power loss – an 80% efficiency means that 80% of the power pulled from the power grid will be converted in power on the power supply outputs and only 20% will be wasted. This translates into less consumption from the power grid (as less power needs to be pulled in order to generate the same amount of power on its outputs), meaning lower electricity bills.

Active PFC (Power Factor Correction), on the other hand, provides a better usage of the power grid and allows this power supply to be comply with the European law, making Corsair able to sell it in that continent (you can read more about PFC on our Power Supply Tutorial). In Figure 1, you can see that this power supply doesn’t have an 110V/220V switch, feature available on power supplies with active PFC.

This power supply uses a very good cooling solution. Instead of having a fan on its back, its fan is located at the bottom of the unit, as you can see in Figure 1 (the power supply is upside down). A mesh replaced the back fan, as you can see. Since the fan used is bigger than fans usually used on power supply units, this unit is not only quieter than traditional power supplies, but also provides a better airflow.

In Figure 3, you can see this power supply modular cabling system, used by its peripheral cables. In Figure 4, you can see the peripheral cables that come with this unit.  Corsair made a minor change to the cables that come with this unit since the first time we looked at it (Sep 2006), upgrading the video card power cables from 6-pin connectors to 6/8-pin connectors.

Corsair HX620W Power SupplyFigure 3: Modular cabling system.

Corsair HX620WFigure 4: Peripheral cables that come with this unit.

This power supply comes with 11 peripheral power cables: two 6/8-pin PCI Express auxiliary power cables for video cards (6-pin on older units); peripheral power cables containing two standard peripheral power connectors each; two peripheral power cables containing three standard peripheral power connectors each; two Serial ATA power cables containing three SATA power connectors each; one Serial ATA power cable containing two SATA power connectors; one floppy disk drive "Y" adapter containing one standard power connector at one end and two floppy disk drive power connectors at the other end; and one fan “Y” adapter allowing you to connect two fans to a single peripheral power connector.


Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.