Appendix B-Glossary - Accusys ACUTA User Manual

Appendix B – Glossary
Parallel ATA (Parallel Advanced Technology Attachment)
Formerly referred to simply as ATA, now known as parallel ATA to differentiate it from Serial
ATA. Various versions exist, including ATA (also called IDE), ATA-2 (Fast ATA or Enhanced
IDE /EIDE) and Ultra ATA (Ultra DMA).
Parity
Parity information is redundancy information calculated from actual data values. If any single
piece of data is lost, the data remaining and the parity information can be used together to
compute the lost data. Parity information can either be stored on a separate, dedicated drive, or
be mixed with the data across all the drives in the array.
RAID (Redundant Array of Independent / Inexpensive Disks)
A disk array in which part of the storage capacity is used to store redundant information about
user data stored on the remainder of the storage capacity. The redundant information enables
regeneration of user data in the event that one of the array member disks or the access path to
it fails. See Parity. Different RAID levels offer different data throughput speeds and fault
tolerance (data redundancy). RAID 0 does not feature redundant information but is nonetheless
considered a special type of RAID.
SCSI (Small Computer System Interface)
An interface standard for attaching external devices to computers. SCSI interfaces provide for
data transmission at up to 80 Mbps. You can attach many devices to a single SCSI port.
Serial ATA (Serial Advanced Technology Attachment)
Serial ATA (often abbreviated as SATA or S-ATA) is a advance on the commonly used Parallel
ATA interface for data storage devices. Serial ATA allows data transfer up to 1.5 Gbps. It has
an additional advantage parallel ATA in that cables are thinner, so airflow within computer
cases is less impeded, and can extend to one meter in length (against only 40 cm for parallel
ATA).
USB (Universal Serial Bus)
USB is a standard for transmitting data between devices at high speed - up to 480 Mbps for
USB 2.0. USB supports hot swapping of devices. USB 2.0 is an extension of the original USB
1.1 standard and uses the same connectors. A single port can be used to connect up to 127
external devices.
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