Hard Drives

Robert Rzeszuto

Most people don’t realize just how complex, interesting, and important the hard

drive really is. The hard drive has gone through many important changes throughout its history to become the hard drive we use today. The hard drive records its data in a very complex way, but its still one of the most reliable pieces of technology to store our precious data. The hard drive comes in different interfaces and forms that became more user-­‐friendly as the hard drive progressed. The hard drive is the main device for storing data on a personal computer. IBM first introduced the hard drive in 1956, but they were not used in personal computers until the 1980s. Still in the early 1980s the hard drive was rare and expensive. Not until the late 1980s did it become the standard storage solution in personal computers. Since the release of the first hard drive it has went through incredible changes. Storage increased by 2,700%; today we have drives available with over 1000 GB of space! Hard drives decreased in physical size from 87 cubic feet to .002 cubic feet. The way the drive records data is

through magnetization. The data is recorded on round disks, which are called platters. The platters are made out of a non-­‐magnetic material like aluminum or glass, and are coated with a thin layer of magnetic material. Usually hard drives have multiple platters that spin at 4,200 RPM to 15,000 RPM for high performance drives. The data is read and written by the read-­‐and-­‐write-­‐heads as the platters spin past them;

the heads are able to move in an arc across to the platter by the actuator arm, which allows this signal head to access the whole platter.

Typically when a hard drive is purchased new it comes already formatted at a low level.

Low level formatting is done by the manufacture; it divides the drive into appropriate clusters and sectors. Current drives have sectors of 512 bytes, but recently advanced formatting is being developed which will divide the drive into 4096 byte sectors. High level formatting is done by the end user. There are multiple types of high level formatting, depending on the kind of operating system being used. For example, if the drive is being used for Windows 7, then it will be formatted into NTFS file system. If the drive is being used for a Mac computer then it will be formatted into Journal file system.

Hard drives come in many form factors ranging from 8” to .85”. But the form factors

that dominate today’s market are the 3.5” and the 2.5”. The 3.5” is mainly used in desktop PCs and the 2.5” is mainly used in mobile computers like laptops and netbooks. The highest capacity available for the 3.5” form factor today is 3TB, but there is a 4TB prototype being developed. The highest capacity available for the 2.5” form factor today is 1.5TB. There have been many interface

families being used throughout hard drive history, but in the recent years the most popular are the ATA and SATA. ATA was the first interface to integrate the HDD controller

directly on the drive. Drives prior to this interface had to have a separate controller card. The ATA interface uses a 40-­‐pin ATA connector with a transfer rate of 16 bits of data at a time though the cable. The SATA interface family was designed for higher data transfer rates and for bigger hard drive capacities. SATA is the standard used today in most new PCs. Although some people take the hard drive for granted, it is one of the most important

components of our personal computers. It’s where we store all our important information and rely on it always being there. With all the progress in hard drive technology we are almost certainly guaranteed its not going to fail on us. It’s become smaller, but with a larger capacity and faster. It has also become more user-­‐friendly with the interface advances. Hard drive technology has advanced so much over the past couple of decades, it will be interesting to see what the future holds for this integral part of the personal computer.

Work cited "Hard Drive." Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 23 Aug. 2011. Web.

26 Aug. 2011.