Magnetic tape and magnetic disk both stores the data magnetically. The surface of a magnetic tape and the surface of a magnetic disk are covered with a magnetic material which helps in storing the information magnetically. Both are non-volatile storage. Despite these similarities both differs in many aspects from their appearance to their working, their cost and much more.
The basic difference between magnetic tape and magnetic disk is that magnetic tape is used for backups whereas, magnetic disk are used as secondary storage. Let us discuss some more differences between magnetic tape and magnetic disk with the help of comparison chart shown below.
Content: Magnetic Tape Vs Magnetic Disk
|Basis for Comparison||Magnetic Tape||Magnetic Disk|
|Basic||Used for backup, and storage of less frequently used information.||Used as a secondary storage.|
|Physical||Plastic thin, long, narrow strip coated with magnetic material.||Several platters arranged above each other to form a cylinder, each platter has a read-write head.|
|Use||Idle for sequential access.||Idle for random access.
|Access||Slower in data accessing.||Fast in data accessing.|
|Update||Once data is fed, it can't be updated.||Data can be updated.|
|Data loss||If the tape is damaged, the data is lost.||In a case of a head crash, the data is lost.
|Storage||Typically stores from 20 GB to 200 GB.||From Several hundred GB to Terabytes.
|Expense||Magnetic tapes are less expensive.||Magnetic disk is more expensive.|
Definition of Magnetic Tape
Magnetic Tapes were introduced in 1928, earlier used as a secondary storage medium. Magnetic tape is a thin long narrow plastic strip coated with the magnetizable substance. The tape is wounded over a spool, and it is wounded or unwounded past a read-write head to read from or write data to the tape.Magnetic Tapes are nonvolatile in nature and hence it holds the large quantity of data permanently. The magnetic tapes store the data sequentially. The random access to magnetic tapes takes more time than magnetic disk because the magnetic tape has to perform forward and rewind operation to locate a correct spot.
Once the read-write head in magnetic tape is positioned correctly, it writes the data with the same speed as that of the magnetic disk. The data transfer speed of the magnetic tape is similar to the magnetic disk. As random access to magnetic tapes is comparatively slower, it was not very useful for secondary storage. Now, the magnetic tapes are used for backups, for storing the data that is less frequently used.
Magnetic tapes are also used in supercomputer centres for holding the large volume of data that is used for scientific research.
Definition of Magnetic Disk
In modern computers, Magnetic Disk is used for secondary storage. Like Magnetic tape, the magnetic disk is also a non-volatile so, its stores the data permanently. The magnetic disk has several flat circular shaped platters which appear like a CD.The diameter of each platter ranges from 1.8 to 5.25 inches.Both inner and outer surfaces of the platter are covered with the magnetic material so that information can be recorded magnetically on the platters. There is a read-write head that moves over the surfaces of each platter. These read-write heads are attached to the disk arm that helps in moving all heads as a single unit.
Each platter surface is divided into circular tracks which are further divided into sectors. The read-write head flies over the platter surface on a thin cushion of air. Though the disk platter is coated with a protective layer, there is always a danger that head will make contact with the disk causing head crash. The Head crash is not repairable the whole magnetic disk is to be replaced.
Key Differences Between Magnetic Tape and Magnetic Disk
- The magnetic tapes are used for backups and the storage of the data that may be less frequently used. On the other hands, the magnetic disk is used as a secondary storage in modern computers.
- The magnetic disk has several platters arranged one above the other to form a cylinder, and each platter has a read-write head that flies over the surface of the platter.On other hands, magnetic tape is a long thin narrow plastic strip coated with magnetizing substance wounded over a spool.
- Magnetic tape allows fast sequential accessing but is slower in random accessing. However, the magnetic disk is fast in accessing data sequentially or randomly.
- Magnetic disk access the data faster than the magnetic tape.
- Magnetic tape can not be updated once written whereas, magnetic disk can be updated.
- If the magnetic tape is damaged data can be lost whereas, in the case of the magnetic disk a head crash can cause data loss.
- Magnetic tape has a storage capacity of 20 GB to 200 GB whereas, the storage capacity of the magnetic disk if from several hundred GB to Tera bytes.
- Magnetic tape is less expensive as compared to the magnetic disk.
Magnetic tape was earlier used as secondary storage, but now they are used for backups. Magnetic disks are used as secondary storage for modern computers. Both Magnetic tapes and magnetic disks are the non-volatile storages and both stores the data magnetically.