Hard Drive Interface Standards
A hard drive interface represents the connection method used by the hard drive to communicate with the computer. A computer’s performance is directly related to the speed of the hard drive unit, so the development of hard drive interface standards represents a key element in the PC evolution process. Speed and ease of use were the two main things the producers kept in mind when developing new interface standards.
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Legacy
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The first hard drive interfaces were the so called hard-cards. These cards consisted of a hard drive mounted directly on a controller board which was inserted into an ISA port. Their biggest advantage was their ease of mount, as you just had to insert the whole hard-card into a free ISA slot.
Evolution
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At one point, manufacturers realized they didn’t have to keep the hard drive on the board, and that’s how the ATA appeared. IBM first used it in 1986. The name ATA comes from their IBM PC/AT computer, ATA standing for AT Attachment. They moved the hard drive away from the board and integrated the controller into the drive, connecting the drive to the board with a 40-pin cable.
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ATA
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Different standards meant different speeds. Starting with the first generation of ATA, which only gave a 4.3 Mb/s data-transfer rate, the speeds kept increasing. Future versions of ATA reached 13.3 Mb/s, 16.6 Mb/s, 33 Mb/s, 66 Mb/s, 100 Mb/s, and finally 133 Mb/s with the last version. After the last ATA version, formerly known as ATA7, the SATA Standard was introduced by the Serial ATA Working Group in 2002.
SATA
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The SATA Standards used only a 4-pin cable but their speeds were much greater compared to the ATA standard. The first version of SATA gave speeds of 150 Mb/s, while the second generation went up to a 300 Mb/s transfer rate. The third generation, released in 2009, delivered a transfer rate of 600 Mb/s. A great feature introduced with the SATA Standard is the ability to hot-swap, which meant a hard drive could be added or removed without having to shut down the PC.
SCSI
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Another standard, launched in the same period as the ATA, is the SCSI interface. Delivering higher speeds and performance than the ATA, SCSI was mostly used at that time by enterprises because of its higher price.
External Solutions
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External solutions were introduced for backup or easy data carrying. The first technology used for this purpose was FireWire. Released in 1995 by Apple, the FireWire standard was also used for printers, digital cameras and other devices. The next standard was USB 2.0. It was released in 2000 and offered greater speeds than the first version, quickly becoming the most widely used method for connections not only for hard drives, but for most computer peripherals as well. eSATA is the external solution provided by the Serial ATA Working Group, the creators of the SATA standards, offering six times greater speeds than USB or FireWire.
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