Hard Drive Glossary

Access refers to the process of retrieving data from or writing data to a data storage device.

The American National Standards Institute (ANSI) is an organization that develops and publishes voluntary consensus standards for various industries in the United States.

Advanced Technology Attachment (ATA) is a standard interface for connecting storage devices like hard drives to computer systems. Originally designed for embedded fixed-disk storage on IBM AT-compatible PCs, ATA has become the dominant storage interface.

A bit is a binary digit, which is the basic data unit for digital computers. It can only contain the value 1 or 0.

A buffer is a temporary storage area used to compensate for differences in data transfer or processing rates between sender and receiver.

A byte is a unit of digital information consisting of eight bits.

A cache is a small, fast memory area (usually DRAM) on the hard drive used to store temporary data that has recently been accessed or is awaiting writing to the disk.

Capacity refers to the amount of data that can be stored in a given storage device, usually expressed in bytes.

A channel, in the context of a data cable, is a collection of electronic circuits that facilitate data writing and reading processes to and from magnetic media.

Data is an organized collection of information.

A gigabyte (GB) is a unit of storage. In the decimal system, 1 GB is equal to 1,000,000,000 bytes, while in the binary system, it equals 1,073,741,824 bytes. Hard drive manufacturers typically use the decimal system, while operating systems use the binary system, leading to discrepancies in reported hard drive capacities.

Jumpers are used to set a hard drive’s attributes, such as Master/Slave. They act as simple on/off switches, connecting two pins to close a circuit. Different combinations of jumpers result in different settings.

Latency refers to the delay between making a request and receiving the corresponding response. Lower latency is preferable.

A megabyte (MB) is a unit of storage. In the decimal system, 1 MB equals 1,000,000 bytes, while in the binary system, it equals 1,048,576 bytes. Hard drive manufacturers and operating systems use different systems for calculating storage capacity, which can lead to discrepancies.

PATA, or Parallel ATA, is an older hard drive interface standard that uses a 16-bit parallel connection to link storage devices and motherboards. It is also known as IDE or EIDE (Enhanced Integrated Drive Electronics). Two popular PATA standards are ATA-6 (also known as Ultra ATA 100 or Ultra DMA 100) and ATA-133, with maximum bandwidths of 100 MB/s and 133 MB/s, respectively.

Serial ATA (SATA) is a hard drive interface standard that uses serial signaling technology to connect storage devices to computer systems. SATA offers several advantages over PATA, including longer, thinner cables for better airflow within computer chassis, fewer pin conductors for reduced electromagnetic interference, and lower signal voltage for minimized noise margin. SATA also provides greater bandwidth, with SATA 1.0 reaching 1.5 Gb/s (150 MB/s) and SATA 2.5 supporting up to 3 Gb/s (300 MB/s).

SCSI is a standard interface for transferring data between devices and computers. Its ability to compartmentalize diverse operations makes SCSI well-suited for multitasking operating environments. When multiple devices are connected, SCSI