Everything You Need to Know About Power Supplies - Power Plugs (Cont’d)

Power Plugs (Cont’d)

PCI Express auxiliary power connectors: These connectors are used to provide more electrical current to PCI Express devices, especially video cards. Therefore, they are also called video card power connectors or simply PEG (PCI Express Graphics). Not all video cards require extra power, but if your video card has this kind of plug you must install the power supply auxiliary power connector. These connectors can have six or eight pins. Almost all video cards that need extra power require the 6-pin version of this connector; only very high-end video cards require the 8-pin type. Some very high-end video cards can even require the use of two auxiliary power cables to feed them. You must pay close attention to the 8-pin connector, because it looks a lot like the EPS12V connector. Though in theory, you can’t insert an EPS12V plug on a video card, if you push really hard, this connection becomes possible. However, it can also lead to a massive short-circuit. Fortunately, all power supplies have a short-circuit protection and won’t turn on if you make this mistake. On the EPS12V connector, the +12 V (yellow) wires are located on the same side of the small latch present on the connector, while on the 8-pin video card power plug, the ground (black) wires are the ones located in that position. Currently, all power supplies must have at least one 6-pin plug, with higher-wattage models providing two, three or four cables, providing extra power to more than one video card or additional power for the very high-end video cards that require two power cables. You can also transform any standard peripheral power plug into a video card power connector through an adapter. This is quite handy if you are installing an additional video card or have an old power supply and don’t want to replace your unit.

Figure 13: The six-pin PEG connector. This particular power supply provides two extra pins for you to transform this 6-pin plug into an 8-pin one. We call this kind of connector a 6/8-pin connector.

Figure 14: A six-pin PEG connector on a video card.

SATA power connectors: This kind of plug is used to provide power to serial ATA (SATA) devices such as hard disk drives and optical disk drives. If your power supply doesn’t have enough of these plugs for your system, you can convert any standard peripheral power plug into a SATA power plug through the use of an adapter. Physically, it is flat and has 15 pins.

Figure 15: SATA power plug.

Figure 16: SATA power connector on a hard disk drive.

Peripheral connectors: This is a 4-pin trapezoid-shaped general-purpose power connector that is frequently used to feed hard disk drives, optical drives, fans, lightning systems, etc. Though currently, new hard disk drives and optical drives are connected to the power supply through SATA power connectors. Before the release of the PEG connector, high-end video cards used this kind of plug for providing extra power to the card. These connectors have existed since the very first IBM PC from 1981, and IBM used a company called Molex as their vendor for them. Many people called these plugs “Molex,” only because on the first PCs, you could read “Molex” on them. People thought this was the name of the connector, not realizing that Molex was the manufacturer. We prefer to call them “standard peripheral power plugs.”

Figure 17: Standard peripheral power plug.

Figure 18: Standard peripheral power connector on an optical unit.

Floppy disk drive power connector: This is the smaller version of the previous plug, used to provide power to 3.5” floppy disk drives. A few older video cards used this plug to provide extra power to them instead of using the previous connector.