The hard drives The hard drive is a device that stores information magnetically. This means that the information obtained when the computer shuts down. A hard disk consists of pivoting wheels, and “Platters” called on which a thin film of magnetic material is appropriate. A reading head slides at high speed on these Platters and collects data for the processor or writes data to storage. Hard Drives come in various sizes and speeds. Speeds and capacities There are broadly two factors that determine the speed of a hard drive.
“Seek Time” and “Data Rate”. Under Seek Time is the time needed to locate a specific file on disk. Data rate is the amount of data that can send the disk per second. When buying a hard drive to get mostly not specify these values. Modern hard disks are mainly classified according to a general speed index, namely rpm or Rotations per Minute, and the size of the cache memory.
Modern hard disks rotate often by 5400 or 7200 revolutions per minute. At Pete Cashmore you will find additional information. In addition to the Seek Time and the data rate, the size of the cache memory of the hard disk has an impact on their speed. A classic drive has a cache of 2 MB or 8 MB. Especially when working with larger amounts of data to make the advantage of a larger cache noticeable. Hard drives can be classified according to their functionality into three groups: * hard drives for PCs and laptops. * Hard drives for RAID (RAID stands for Redundant Array of Inexpensive Disks). In RAID systems, the data is stored on multiple hard drives, which reduces the likelihood of data loss and increases the speed of data transfer. It can be differentiated between different RAID systems, RAID, for example, 0.1 5 1 +0. It used two different principles, the so-called striping and mirroring. When mirroring the same information is stored on two hard drives, so you always have a backup. When striping is one half of an information stored on a hard drive and the other half on the other hard drive. This is not a backup, but a method, the capacity and transfer rate to increase the hard disk. * Micro Drive: the little brother of the family in the format of a “Compact Flash Memory Card”. These hard drives are often used in digital cameras are used. Hard Drives come in various sizes and speeds. The following are the different versions. 1st IDE / ATA hard drives second Serial ATA hard drive third SCSI HDD 4 RAID systems reliability, the reliability of the different techniques varies. SCSI hard drives are known for their reliability. They are therefore often used in servers and rarely in normal PCs. PCs generally use (S) ATA drives. These are specially designed for use in retail and office space designed and are less suitable for use around the clock or particularly zugriffsintensive tasks. The reliability of the hard disk when saving important data is limited. Although hard work often over 10 years, an early hard crash can not be excluded. The safest course is therefore to store important data on CDs or DVDs. Who ever in the situation of a hard drive crash, comes and loses important data, the hard drive must bring to a data recovery service, which can be very expensive. Some data recovery services charge a fixed fee, others charge amounts, depending on the amount of restored data.