To provide power to large internal Devices such as hard drive or CD/DVD drives and sometimes case fans or other devices.Just adding this.Powers IDE drives.
The power connectors used by both 5.25-inch and 3.5-inch floppy drives are 4-pin connectors. The larger connector--used by 5.25-inch drives--is called a Molex or peripheral cable. This type of cable is also used by IDE/ATA hard drives and optical drives. The smaller 4-pin cable used by 3.5-inch floppy drives is generally called a floppy power cable.
Notebook's use 2.5 hard drives and they have 44 pin connections 3.5 hard drives used 40 pin connections BUT they make adapters to use either or
It has 40 Pins
There are two kinds in common use:Molex - an older standard, but still commonSATA - Serial ATA, a newer standardSee the related links for pictures.
It has 40 Pins
A Molex power connector is a 4-pin power connector found in most computer power supplies. It is used to provide power to large internal drives like hard drives and CD/DVD drives. They are slowly being replaced by SATA power connectors, which are easier to install can cannot be inserted incorrectly. They should not be confused with a Berg connector which is much smaller and is used to power floppy drives. The molex connector is used for IDE drives
PATA stands for Parallel AT Attachement. It typically uses an 80-pin connector (ATA-5 cable) with 40 pins as the signals and the other 40 pins as grounds. Its also uses a 4-pin molex power connector. This drive is identical to the ATA IDE we used to rememeber, nothing changed other than the name. However, with the advent of the SATA drives, we needed change to avoid confusion. The things to rememebr is that PATA uses a wide flat parallel interface cable, 80-pins, 4-pin power cable, whereas, the SATA (Serial AT Attachement) uses a 7-pin interface connector, and a 15-pin power conector. The SATA drives are much faster, lower temperatures and lower voltages. The IDE in the drives are identical as well. It means Integrated Drive Electronics. This is the actual electronics within the drive to make it spin/control the read and write access times.
It depends, ones for hard drive are i think, about 40 pins, an less for the floppy IDE cable Desktop hard drives have "40" pin connectors; however, the actual number of pins is 39. There is one pin missing in the upper row, middle. I believe the reason for this is so the ribbon won't be connected upside down, it can only go one way.
Molex Connectors are used in Power Supplies for powering up the devices. There are different types of Molex Connectors on Power Supply for. eg. 20 or 24 Pin Power Connector\ 4 Pin IDE device \ Sata Device Connector.Mini Molex refers to connector powering Floppy Disk Drives or AGP Cards on Computer System.
Colour doesnt matter for the IDE. It is the number of pins that are available in the IDE slot If it is a 40pin IDE, it will support HDD and CD/ DVD RAM drives. If it is a 34 pin IDE, it supports the FDD
24 pin connector is required to supply power to the motherboard.