|  The hard disk drive is the primary storage location where data is permanently stored. Below is an illustration of what the inside of the hard disk drive may look like. The four main components of a hard disk drive are the platters, head arm, chassis, and the head actuator. The majority of computer hard disk drives are permanently stored in an internal drive bay at the front of the computer and are connected with one ATA / SCSI cable and power cable. Unlike other drives the hard disk drive is the only drive that is not physically accessed by the user like the floppy disk drive or the CD-ROM drive. The capacity of a computer hard disk drives and the files it contains can be confusing. Below is a listing of the standards in different size values. It is important to realize that not all manufacturers and developers use these values. For example, a manufacturer may consider a gigabyte as the value of a gibibyte. As the primary communication device to the rest of the computer, the hard drive is very important. The hard drive stores most of a computer's information including the operating system and all of your programs. Having a fast CPU is not of much use if you have a slow hard drive. The reason for this is because the CPU will just spend time waiting for information from the hard drive. During this time, the CPU is just twiddling it's thumbs. |
| The hard drive stores all the data on your computer - your text documents, pictures, programs, etc. If something goes wrong with your hard drive, it is possible that all your data could be lost forever. Today's hard drives have become much more reliable, but hard drives are still one of the components most likely to fail because they are one of the few components with moving parts. The hard drive has round discs that store information as 1s and 0s very densely packed around the disc. All hard drives share a basic structure and are composed of the same physical features. | However, not all hard drives perform the same way as the quality of the parts of the hard drive will affect its performance. Following is a description of the common features of the hard drive and how each part works in relation to the others The Platters: The platters are the actual disks inside the drive that store the magnetized data. Traditionally platters are made of a light aluminum alloy and coated with a magnetizable material such as a ferrite compound that is applied in liquid form and spun evenly across the platter or thin metal film plating that is applied to the platter through electroplating, the same way that chrome is produced. Newer technology uses glass and/or ceramic platters because they can be made thinner and also because they are more efficient at resisting heat. The magnetic layer on the platters has tiny domains of magnetization that are oriented to store information that is transferred through the read/write heads. Most drives have at least two platters, and the larger the storage capacity of the drive, the more platters there are. Each platter is magnetized on each side, so a drive with 2 platters has 4 sides to store data. The Spindle and Spindle Motor: The platters in a drive are separated by disk spacers and are clamped to a rotating spindle that turns all the platters in unison. The spindle motor is built right into the spindle or mounted directly below it and spins the platters at a constant set rate ranging from 3,600 to 7,200 RPM. The motor is attached to a feedback loop to ensure that it spins at precisely the speed it is supposed to. |
