IDE, an acronym for Integrated Drive Electronics, is a standard type of connection for storage devices in a computer.
Generally, IDE refers to the types of cables and ports used to connect some hard drives and optical drives to each other and to the motherboard. An IDE cable, then, is a cable that meets this specification.
Some popular IDE implementations that you might come across in computers are PATA (Parallel ATA), the older IDE standard, and SATA (Serial ATA), the newer one.
IDE is also sometimes called IBM Disc Electronics or just ATA (Parallel ATA). However, IDE is also an acronym for Integrated Development Environment, but that refers to programming tools and has nothing to do with IDE data cables.
Why You Need to Know What IDE Means
It's important to be able to identify an IDE drive, IDE cables, and IDE ports when you're upgrading your computer hardware or buying new devices that you'll plug into your computer.
For example, knowing whether or not you have an IDE hard drive will determine what you need to buy to replace your hard drive. If you have a newer SATA hard drive and SATA connections, but then go out and buy an older PATA drive, you'll find that you can't connect it to your computer as easily as you'd hoped.
The same is true for external enclosures, which let you run hard drives outside of your computer over USB. If you have a PATA hard drive, you'll need to use an enclosure that supports PATA and not SATA.
Important IDE Facts
IDE ribbon cables have three connection points, unlike SATA which has just two. One end of the IDE cable is, of course, to connect the cable to the motherboard. The other two are open for devices, meaning you could use one IDE cable to attach two hard drives to a computer.
In fact, one IDE cable can support two different types of hardware, such as a hard drive on one of the IDE ports and a DVD drive on another.
If two devices are connected to the IDE cable simultaneously, the jumpers have to be set correctly.
An IDE cable has a red stripe along one edge, like you see below. It's that side of the cable that usually refers to the first pin.
If you're having trouble comparing an IDE cable to a SATA cable, refer to the image below to see just how large IDE cables are. IDE ports look similar because they'll have the same number of pin slots.
As important as it is to differentiate between PATA and SATA, it's actually impossible to accidentally plug a SATA cable into an IDE slot, or an IDE cable into a SATA slot.
The speed of an IDE-connected device depends not only on its own capabilities but also on the cable being used. For example, if you plug a slow cable into a fast hard drive, the drive will operate only as fast as the cable allows it to.
Types of IDE Cables
The two most common types of IDE ribbon cables are the 34-pin cable used for floppy drives and the 40-pin cable for hard drives and optical drives.
PATA cables can have a data transfer speed anywhere from 133 MBps or 100 MBps down to 66 MBps, 33 MBps, or 16 MBps, depending on the cable. More can be read about PATA cables here: What Is a PATA Cable?.
While PATA cable transfer speeds max out at 133 MBps, SATA cables support speeds up to 1,969 MBps. You can read more about that in our What Is a SATA Cable? piece.
Mixing IDE and SATA DevicesUGREEN USB IDE Adapter.Photo from Amazon
At some point throughout the life of your devices and computer systems, one will probably be using newer technology than the other. You may have a new SATA hard drive, for example, but a computer that only supports IDE.
Fortunately, there are adapters that let you connect the newer SATA device with an older IDE system, like this Kingwin SATA to IDE adapter.
Another way to mix SATA and IDE devices is with a USB device like this one from UGREEN. Instead of having to open the computer to connect the SATA device like with the adapter from above, this one is external, so you can plug your IDE (2.5" or 3.5") and SATA hard drives into this device and then connect them to your computer over a USB port.
What Is Enhanced IDE (EIDE)?
EIDE is short for Enhanced IDE, and is an upgraded version of IDE. It goes by other names, too, like Fast ATA, Ultra ATA, ATA-2, ATA-3, Fast IDE, and Expanded IDE.
EIDE is used to describe the faster data transfer rates beyond the original IDE standard. For example, ATA-3 supports rates as fast as 33 MBps.
Another improvement over IDE that was seen with the first implementation of EIDE was support for storage devices as large as 8.4 GB.