Choosing a Computer Hard Drive
Magnetic storage is used to store and retrieve information from an electro-mechanical data storage which is known as a hard drive. A magnetic material coats the rigid rapidly rotating disks of a hard disk. The other names of hard drive include; a hard disk, hard disk drive and fixed disk. Platters or rotating disks are paired with magnetic heads that are usually arranged on a moving actuator arm that reads and writes data to the platter surfaces. A machine component that results to moving and controlling of a mechanism or system is an actuator. So that the actuator can work it requires a control signal and a source of energy.
An example of a non-volatile storage is the hard drive which retains stored data even when powered off. A non-volatile storage is a type of computer memory that retrieves stored information even when the power is no more. There are examples of non-volatile memory that include; flash memory, hard disk drive, optical discs, floppy disks, read only memory and ferroelectric memory. Traditional non-volatile disk storage or storage in non-volatile memory chips are the classifications of non-volatile memory. However there are performance characteristics of a hard drive which are seek time, rotational latency, bit rate and defragmentation. The creation of delay by bit rate or data transfer rate results to the function of the number of blocks transferred.
The procedure used to minimize delay the retrieval of data by moving related items to physically proximate areas on the disk is defragmentation. Depending on the type of computer, defragmentation will occur automatically. The access of delays is reduced by automatic occurrence of defragmentation but performance of the computer is temporarily inhibited.
The desired disk sector is not directly under the head when the data is transferred in rotational latency. A disk sector is a sub division of a track on a magnetic disk or optical disc. In a hard drive the disk sector is the minimum storage unit. The measure of how long it takes the head assembly to travel to the track of the disc that contains data is the seek time which is another performance characteristic of hard drive.
In addition to the performance characteristics price, power consumption, operating and non-operating shock resistance and audible noise are also considered. There are some guidelines when choosing a hard drive. The first aspect is choosing the correct interface which are the PATA and SATA interfaces. The SATA interface is good for repairs or upgrading of systems that has SATA interfaces while PATA interfaces are good for repairs or upgrading of systems that lack SATA interfaces. The next factor of consideration is choosing a model that has a large cache as they use these to increase performance.