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The system is almost complete. The power supply serves as the beating heart of the computer, driving voltage (and wattage) to all operating devices. Most modern mid- and full-tower cases will mount the PSU in the bottom of the case, though some still run top-mounted PSUs. Small Form Factor (SFF) and mini-ITX cases have unique space constraints that sometimes make for creative PSU location. Generally, though, it’s a bottom mount.
There are three classifications of power supplies:
- Fully Modular: All cables can be disconnected and removed from the PSU, including the 24-pin and 8-pin cables.
- Semi-Modular: All cables except the 24-pin and 8-pin/EPS cables can be removed from the PSU.
- Non-Modular: No cables can be removed, and all are connected directly into the PSU housing. This means that unused cables become excess and must be hidden. Non-modular PSUs tend to be a little bit more affordable as a result.
How to Install a PSU
Step 1 – Determine the location of the PSU
Locate the PSU mounting point within the case. If the case has a PSU shroud, there’s also a good chance that a PSU bracket is included – the bracket is installed to the PSU prior to its mounting in the system, and serves to make the process easier. Shrouds will also conceal the cables – a major benefit, and one which the NZXT S340 and NZXT H440 leverage for cleaner cable management. Hiding the cables behind a PSU shroud also means that it’s difficult to make connections once the unit is installed. To this end, we’d recommend connecting all necessary cables to the power supply (if it is modular) prior to installation.
To determine which cables are needed, have a look over your components.
These are the common requirements of a power supply:
- 24-pin cable for the motherboard (always needed)
- 4/8-pin EPS12V cable for the motherboard, near the CPU (always needed)
- 6/8-pin PCI-e cable for video cards (often needed, but not always; sometimes multiple are required)
- SATA power cable for SATA-attached SSDs (sometimes required – but not for PCI-e/M.2 SSDs)
- MOLEX 4-pin cable for fans and accessories (sometimes required)
Next, figure out how many of each cable you’ll need. Systems with multiple video cards or SSDs/HDDs may need additional cables connected, whereas less complex machines can get away with a minimalistic approach to cables.
Attach those that will be necessary. Don’t connect them just yet – we’ll do that next.
Step 2 – Determine the orientation of the PSU
Now, once the mounting location is found and cables readied, determine the orientation of the PSU. Most bottom-mounted cases will offer ventilation on the underside of the case, generally including a dust filter for preventative maintenance. In these cases, install the PSU with the fan facing down (so that it can breathe – especially important to pay attention to when working with shrouds).
In cases that are top-mounted or with unique mounting locations, check the manual. Generally, the preferred orientation is one which will expose the fan to the outside air for fresh intake. If that is not possible or if the PSU doesn’t butt-up against a side panel, install the power supply with the fan facing down. This is sub-optimal as it will intake warmed air that’s being exhausted through the CPU’s fans (if not using liquid), but is sometimes necessary.
Step 3 – Mount the PSU
Finally, hold the PSU in its final resting position and begin the process of screwing-in the four accompanying screws. These are hex-head Phillips screws (you can also use a hex driver). There should be four installed, in most builds. – GamersNexus
Cable connections are easily the most visually intimidating aspect of system building. On the face of things, it looks like there are an awful lot of connections to be made – but distilling the process down to only the required cables for our build quickly reveals otherwise. Connecting the cables is surprisingly simple once the process has begun.
There are only a few main cables that must be connected:
- 24-pin power to motherboard (always required)
- 4/8-pin EPS12V power to CPU (always required)
- 6/8-pin power to video card (normally required)
- SATA power to storage devices (normally required)
- MOLEX power to accessories (optional)
- CPU fan & case fan power (required)
- Power cable to system’s power supply (always required)
- SATA data to storage (normally required)
- USB2.0 front panel headers (normally required)
- USB3.0 front panel header (normally required)
- HD Audio front panel header (normally required)
- Power switch [PWR_SW]
- Reset switch [RESET]
- Power LEDs [PWR_LED]
- Hard Drive LEDs [HDD_LED]
Here’s how the PSU cables should look:
How to Connect PSU Cables
- Connect your power supply cables beginning with the 24-Pin Motherboard connector.
- Next, connect the 8-Pin CPU/ Motherboard cable. Some motherboards will only require a 4-Pin connector.
- Next, connect the 6 or 8-Pin PCI power cable to your video card. Some video cards do not require additional power from the power supply. Some video cards will require two 6 or 8-Pin PCI power cables.
- Next, connect your storage or disk device such as your HDD, SSD, or DVD Drive. Connect the SATA data cables that were included with your motherboard. Connect one end to the hard drive or disk drive and the other end into the appropriate SATA slot on your motherboard. Consult the manual for additional instructions on which slot to use.
- Connect the SATA power cable from the power supply to the drives.
- Connect any USB headers from your accessories such as the GRID+ or Aperture M Card Reader.
- Connect the SATA or MOLEX power for any of your accessories or coolers such as the SATA power connector in the Kraken™ liquid cooler.
- Connect the USB 3.0 connector to enable the USB 3.0 slots on the outside of your case. (If there are any)
- Connect the HD Audio and USB headers to enable the USB 2.0 and Headset / Mic ports on the outside of your case.
- Connect the Power SW, Reset SW and LED indicator headers into the motherboard to enable the activity LEDs and power / reset buttons on your case.
How to make everything clean with cable management
- Pull any excess cabling through the rubber grommets to ensure the PC is nice and clean from the front.
- Organize the remaining bundles of cables and begin zip tying them to the case using the zip-tie points.
- Arrange your cables into a group without overlapping or tangling them.
- Zip tie them together to the back of the case to create a neat and slim profile.
- Gather excess cabling together and tuck them away in an empty space such as an unused hard drive mount in front of the power supply.
- Continue arranging cables and zip tying them to the case until you are happy with your result.
- Close the side panel and make sure any excess cables are out of view from the front of the case.
That wraps the most common connections in a PC build! At this point, it’s all about cable management and cleanliness – but that’s just a matter of spending the time on it. – GamersNexus