Choosing a Computer Hard Drive
A hard drive is the electro-mechanical data storage device that uses magnetic storage to store and retrieve digital information. A magnetic material coats the rigid rapidly rotating disks of a hard disk. A hard drive is also known as a hard disk, hard disk drive and fixed disk. The arrangement of magnetic heads that are paired with platters 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.
Storing of data even when powered is done by a hard drive as it is a type of non-volatile storage. Stored information can be retrieved by using a non-volatile storage is a type of computer memory. There are examples of non-volatile memory that include; flash memory, hard disk drive, optical discs, floppy disks, read only memory and ferroelectric memory. In addition the non-volatile memory can be classified as either traditional non-volatile disk storage or storage in non-volatile memory chips. Seek time, rotational latency, bit rate and defragmentation are the performance characteristics of a hard drive. Based on the number of blocks transferred, bit rate or data transfer rate is resulted from the creation of delay.
Defragmentation is the procedure used to minimize delay the retrieval of data by moving related items to physically proximate areas on the disk. Different types of computers have automatic defragmentation. 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 sub division of a track on a magnetic disk or optical disc is referred to a disk sector. 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 interface types are PATA and SATA and need to be chosen correctly. The only difference between PATA and SATA interfaces is that SATA interface are 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. Performance is increased by use of cache and thus when choosing a hard drive, the model needs to have a large cache.