Hard Drives

COMP1260 > Hardware

Introduction The hard drive (also called a hard disk) is the primary computer storage device, which reads and writes on one or more platters. Hard drives are found in desktop and laptop computers as well as in servers and other mainframe computers. Although removable hard drives in cartridges use the same media and similar drive technology, they are usually called external hard drives - see External Storage. Opened Hard Drive

...by students The first thing I do when buying a computer or laptop, is check its hard drive capacity, RAM size and CPU performance. The capacity of the hard drive is important to me, since I store a lot of music, pictures, and videos which all require a fair amount of memory. Recently, I had to purchase an external hard drive because I couldn’t store all my data on my 80GB laptop hard drive. The thing I don’t like about having an external hard drive is that whenever I go somewhere with my laptop and would like to access the data on my external drive, I have to carry it with me. It only takes about 20 DVD videos to fill up 100GB of memory space. Now that you can watch videos on Blue-Ray disks that take up even more memory space, a hard drive with a memory capacity of 1TB (1000GB) could eventually be your next optimal hard drive.

How Hard Drives work:

A hard drive usually consists of several mirror smooth platters (or disks). Each platter can be read and written from both sides by extremely light and fast heads, moved by an arm that is controlled by a mechanism at a corner of the hard drive. The arm of a hard drive can move from the hub to the edge and back up to 50 times per second.

Hard drives come in all kinds of sizes. Most Desktop Computers today use 3.5 inch platters whereas laptops and other mobile technologies use a smaller platter size, usually 2.5 inches. Hard drives usually operate at 5400 RPM on laptops and 7200 RPM and higher on Desktop Computers. .

Most non-volatile hard drives used today are not solid state hard drives. This means that these hard drives still contain movable parts, like platters and moving arms, which can be easily damaged when not being handled with care. Some of today’s computers already contain a Solid State Drive, which has no moving parts. The Solid State Drive works similarly as to how a flash drive would works. A Solid State Drive is more expensive and its memory capacity is quite limited, but therefore it is smaller in size, operates soundless, and offers a safer data storage.

Function of a Hard Drive:

The hard drive in a Computer is able to store a large amount of data for any given period of time without any energy consumption meaning that it is non-volatile, unlike memory devices used in a computer that require constant energy supply. For example, RAM is used for storing data, but it is only able to store data when having constant power supply. As soon as the RAM's power supply stops all data stored on it will be lost.

History:

Most hard drives used today are not solid state hard drives. This means that these hard drives contain movable parts like rotating platters and moving arms which can be easily damaged when not being handled with care. Some of today’s computers already have Solid State Drives (SSD) that have no movable parts and operate similarly to a Flash Drives. Solid State Drives compared to conventional hard drives wear out slower, don’t break as easily and have less power consumption, but its storage capacity can be very limited. As of 2008, Solid State Drives can be bought with a storage capacity of 64GB, and with storage capacity doubling every 1 to 2 years, Solid State Drives will be very common in future.

References/Further Readings

http://en.wikipedia.org/wiki/Flash_drive
http://en.wikipedia.org/wiki/Hard_drive
http://en.wikipedia.org/wiki/Solid-state_drive
http://en.wikipedia.org/wiki/IBM_305_RAMAC

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