Drive bay
Encyclopedia
Computer hardware
Personal computer hardware are component devices which are typically installed into or peripheral to a computer case to create a personal computer upon which system software is installed including a firmware interface such as a BIOS and an operating system which supports application software that...
to a computer. Most drive bays are fixed to the inside of a case, but some can be removed.
Over the years since the introduction of the IBM PC
IBM PC
The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
, it and its compatibles
IBM PC compatible
IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...
have had three types of drive bay, of which two are in common use today.
5.25″
Full-height bays were found in old PCsIBM PC compatible
IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...
in the early to mid-1980s. They were 3¼″ high by 5¾″ wide, and up to 8″ deep (3.25 x), used mainly for hard disk
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...
s and floppy disk
Floppy disk
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...
drives.
Half-height drive bays are 1⅝″ high by 5¾″ wide (1.625 by 5.75 in (41.3 by 146.1 mm)), and are the standard housing for CD
Compact Disc
The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...
and DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....
drives in modern computers, but were sometimes used for other things, including hard disk
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...
s and floppy disk
Floppy disk
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...
drives in the past. It is important to note that the name does not refer to the width of the bay itself, but rather to the width of the disks used by the floppy drives which mounted in these bays. Often represented as 5¼-inch.
The dimensions of a 5.25″ drive are specified in the SFF standard specifications [ftp://ftp.seagate.com/pub/sff/SFF-8500.PDF SFF-8500] and [ftp://ftp.seagate.com/pub/sff/SFF-8501.PDF SFF-8501] which were incorporated into the EIA-741 specification by the Electronic Industries Association (EIA).
3.5″
3.5″ bays, like their larger counterparts, are named after diskette dimensions; their actual dimensions are 4″ wide by 1″ high (4 by 1 in (101.6 by 25.4 mm)). Those with an opening in the front of the case are generally used for floppy or ZipZip drive
The Zip drive is a medium-capacity removable disk storage system that was introduced by Iomega in late 1994. Originally, Zip disks launched with capacities of 100 MB, but later versions increased this to first 250 MB and then 750 MB....
drives. Hard drives in modern computers are typically mounted in fully internal 4″ (nominally 3.5″) bays. They are limited to 0.7″ (0.7 inches (17.8 mm)) height to allow room for airflow. Of course, nowadays most computers—especially laptops—don't come with floppy drives at all since CD
CD-RW
A CD-RW is a rewritable optical disc. It was introduced in 1997, and was known as "CD-Writable" during development. It was preceded by the CD-MO, which was never commercially released....
/DVD-RW
DVD-RW
A DVD-RW disc is a rewritable optical disc with equal storage capacity to a DVD-R, typically 4.7 GB. The format was developed by Pioneer in November 1999 and has been approved by the DVD Forum. The smaller Mini DVD-RW holds 1.46 GB, with a diameter of 8 cm.The primary advantage of DVD-RW over...
drives are very common. There are adapters, sometimes called a "sled", which can be used to mount a 3.5″ device in a 5.25″ bay. Often represented as 3½-inch.
The dimensions of a 3.5″ drive are specified in the SFF standard specifications [ftp://ftp.seagate.com/pub/sff/SFF-8300.PDF SFF-8300] and [ftp://ftp.seagate.com/pub/sff/SFF-8301.PDF SFF-8301] which were incorporated into the EIA-740 specification by the Electronic Industries Association (EIA).
Usage
Drive bays are most commonly used to store disk drives, although they can also be used for front-end USBUniversal Serial Bus
USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....
ports, I/O bays, card reader
Card reader
A card reader is a data input device that reads data from a card-shaped storage medium. Historically, paper or cardboard punched cards were used throughout the first several decades of the computer industry to store information and programs for computer system, and were read by punched card readers...
s, fans
Computer fan
A computer fan is any fan inside, or attached to, a computer case used for cooling purposes, and may refer to fans that draw cooler air into the case from the outside, expel warm air from inside, or move air across a heatsink to cool a particular component...
, tool storage, and other uses. Some computers have a small system monitor
System monitor
A system monitor is a hardware- or software- based system used to monitor resources and performance in a computer system.Software monitors occur more commonly, sometimes as a part of a widget engine. These monitoring systems are often used to keep track of system resources, such as CPU usage and...
LCD display mounted in a drive bay.
When installing a drive in a bay, it is usually secured with 4 screws that hold the drive in the bay, although toolless fasteners are becoming more common. Then, any necessary power, data transfer, and other cables are routed into and connected to the rear of the drive. The drive bay is usually just big enough for the drive to fit inside.