COMPUTER AND IT : HARD DISK AND TYPES

Sunday, 2 August 2015

HARD DISK AND TYPES

When you save data or install programs on your computer, the information is typically written to your hard disk. The hard disk is a spindle of magnetic disks, called platters, that record and store information. Because the data is stored magnetically, information recorded to the hard disk remains intact after you turn your computer off. This is an important distinction between the hard disk and RAM, or memory, which is reset when the computer's power is turned off.

The hard disk is housed inside the hard drive, which reads and writes data to the disk. The hard drive also transmits data back and forth between the CPU and the disk. When you save data on your hard disk, the hard drive has to write thousands, if not millions, of ones and zeros to the hard disk. It is an amazing process to think about, but may also be a good incentive to keep a backup of your data.

ATA (IDE, ATAPI, PATA)

ATA is a common interface used in many personal computers before the emergence of SATA. It is the least expensive of the interfaces.

Disadvantages

Older ATA adapters will limit transfer rates according to the slower attached device (debatable)
Only ONE device on the ATA cable is able to read/write at one time
Limited standard for cable length (up to 18inches/46cm)

Advantages

Low costs
Large capacity

SATA

SATA is basically an advancement of ATA.

Disadvantages

Slower transfer rates compared to SCSI
Not supported in older systems without the use of additional components

Advantages

Low costs
Large capacity
Faster transfer rates compared to ATA (difference is marginal at times though)
Smaller cables for better heat dissipation

SCSI

SCSI is commonly used in servers, and more in industrial applications than home uses.