Types of IDE Hard Drives

The IDE, or integrated drive electronics, interface is a computer drive data transfer specification introduced by the Western Digital Corporation in 1986. Commonly known today as parallel ATA, due to a retroactive renaming in light of the Serial ATA specifications release, the IDE data transfer specification has been antiquated by technologies such as Serial ATA and eSATA. IDE drives were used extensively in desktop, laptop and workstation computers for 17 years.

History

The first version of the IDE interface was released by Western Digital for development in cooperation with the Control Data Corporation and Compaq computers. Compaq computers were the first systems to utilize this type of hard drive in 1986. The term IDE referred not only to the cable connector and cable itself, but also to the hard drive controller. The IDE specification was the first to place hard drive controllers on the drive housing itself. Until this point, the controllers were installed on computer motherboards as opposed to the drives themselves.

Function

IDE hard drives act as a mass storage area within a computing solution to store permanent data such as operating systems, applications and user data files. Under the Windows operating system, IDE hard drives--with virtual memory enabled--act as an extension to the system's main memory. The IDE specification also included a disc lock feature to facilitate the IDE drive's use as a secure off-site backup medium.

Desktop IDE drives

Desktop computers utilizing the IDE hard drive specification could attach up to four hard drives into a computing solution without the need of a hard drive controller card. IDE hard drives for desktop computers had a rotational speed between 5,400 and 7,200 RPM. Desktop computer motherboards contained two IDE channels that supported up to two IDE devices each.

Laptop IDE hard drives

Laptop IDE hard drives are usually either 1.8 or 2.5 inches in size, as opposed to the 3.5-inch size used by desktop computers. IDE hard drives for laptops had a rotational speed of 5,400 RPM; sometimes lower proprietary speeds were set by OEM manufacturers in order to make the drives use less power and extend laptop battery life. Under most circumstances, laptops only supported one IDE drive. Due to limited space for housing internal devices, they can be removed for upgrade or replacement.

Workstation IDE drives

Workstation computers used IDE drives that were identical to desktop drives with the exception of having rotational speeds up to 10,000 RPM. Workstations often used independent secondary IDE controller cards in order to combine several physical disks into one logical disk within the system. In order to achieve this end, these controller cards often supported some form of RAID (redundant array of independent disks). In doing this, workstations were able to combine the speeds of several IDE hard drives to support mission-critical applications.

References

• Overview and History of the IDE/ATA Interface
• Western Digital Enhanced IDE Interface