Hard Drive First Storage

Secondary Storage is data storage on hard disk, tapes, and other external devices. It is technically known as mass storage or just, storage or external memory, which is different from primary storage, and is not directly accessible to CPU. Computer use its input/output channels to access the information from secondary storage. Secondary storage is of permanent nature, and it is used for long-term data storage. Secondary storage is slower, but has much greater capacity than primary storage. Secondary Storage devices include – Flash memory, Floppy disk, Hard disk drive, Magnetic tape, Optical disc drive, Paper tape, Punch card, RAM disk, USB flash drive, and Zip Drive.

Hard Drive is defined as computer hardware that holds and spins a magnetic or optical disk and reads & writes information on it. It is a non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces. It is also referred to as hard disk drive (HDD), hard disk or fixed disk drive.

Hard Drive stores information on one or more rigid, flat, disks, which are technically termed as “platters” or “hard disk platters”. HD Platters are the circular disks with magnetic surfaces where the magnetic data are stored. Hard disk is sealed to prevent dust and other foreign materials.

Originally developed for computer usage, the early fixed disk drives had removable media. They were large, cumbersome devices, more suited to use in the protected environments. Most disk drives before the early 1980s had 8-inch (20 cm) or 14-inch (35 cm) platters. They required an equipment rack or a large amount of floor space, especially the large removable-media disks, which were often referred to as “washing machines”. That is why, many early PCs came without hard drives; the original IBM PC (IBM 5150) was not equipped with a hard disk drive. The early hard drives also had smaller capacities in megabytes. Seagate Technology introduced the ST-506, the first 5.25-inch Hard Drive, with a capacity of 5 megabytes. Hard drives became popular and became available on retail store shelves by the mid-1990s.

Today’s hard drives are typically sealed units with fixed media. In the 21st century, the use of these storage devices expanded. They were widely used in digital video recorders, digital audio players, personal digital assistants, digital cameras, and video game consoles. Samsung and Nokia introduced the first mobile phones with hard drives in 2005. The configurations, such as RAID arrays, network attached storage (NAS) systems and storage area network (SAN) systems, which provide efficient and reliable access to large volumes of data, came to cater the need for large-scale, reliable storage, independent of a particular device.

The capacity of hard drives is usually measured in gigabytes. Their size is measured inches. The majority of drives used in desktops today are 3.5" wide, while those used in laptops are 2.5" wide.

Up to 2005, some of the commonly used hard drives were 30 GB, 40 GB, 60 GB, and 80 GB. In the attempt to enhance recording density and throughput, disk drives with perpendicular recording technology were produced in 2006.

In the recent times, hard drives have been produced in varying sizes and capacities. Recently, 160 GB drives have also been produced. Hitachi was first to market the first 3.5" Hard Drive with 1 TB capacity – Hitachi Deskstar 7K1000. The drive contains five platters at approximately 200 GB each, providing 935.5 GiB of usable space. Hitachi has since been joined by Samsung and Seagate in the 1 TB drive market.

Some of the largest capacity hard drives available in 2007 include – 5.25" FH 47 GB (146 mm width) with 14 platters, 5.25" HH 19.3 GB Hard Drive (146 mm) with 4 platters, 1.8" (PCMCIA) 160 GB Hard Drive (54 mm width), 1.8" (ATA-7 LIF) 160 GB Hard Drive (53.8 mm width), 2.5" 320 GB Hard Drive (69.9 mm width) with 3 platters, and 3.5" 1.2 TB Hard Drive (102 mm width) with 5 platters. Manufacturers have started selling SATA and SAS 2.5 inch drives for use in servers and desktops. The 1.8" ATA-7 LIF providing 160GB storage capacity, is often used inside digital audio players and subnotebooks.

Over 98% of the world's Hard Drives are manufactured by just a handful of large firms, such as Seagate, Western Digital, Samsung, and Hitachi, which owns the former disk manufacturing division of IBM. Fujitsu manufactures mobile and server-class disks. Toshiba is a major producer of 2.5-inch and 1.8-inch notebook disks. ExcelStor is a small HDD manufacturer.