ICT Hardware

ICT Hardware

CD ROM

A CD-ROM drive uses a round shaped optical disc, which is used to store different types of data, applications, games and audio files. The disc of a CD-ROM is known as a CD, CD-ROM disk or just disk. The data storage capacity of a CD is 700 MB.

Apart form its high storage capacity, a CD is very reliable. These factors have ensured its widespread use in most organizations. Using a single a CD not only saves times, but also makes the process of installing of software easier. CD-ROM drives have a variety of controls on their front panel. Some of these controls are :

  • Headphone Jack: Connects a headphone to a CD-ROM drive and allows you to listen audio
  • Volume Control Button: Controls the volume of the connected headset.
  • Eject Button: Ejects a CD or CD Tray.

A CD-ROM drive can be classified by the X factor, which refers to the speed or rate of data transfer of the drive. For example, 1x refers to single speed, 2x refers to double speed, 4x to quad speed and so on. The following table shows the transfer rate of different CD-ROM drives.

Type of CD-ROM Drive Transfer Rate in KB/Sec
1x 150
2x 300
4x 600
8x 1200
10x 1500
12x 1800
16x 2400
24x 3600
32x 4800
36x 5400
40x 6000
48x 7200
52x 7800
56x 8400
72x 10800

The working of a CD-ROM drive depends on several factors, such as the type of microprocessor, capacity of Random Access Memory (RAM) and type of video card installed on a computer. Just having a faster CD-ROM drive does not necessarily mean that the drive is performing optimally. For that, you must ensure that all the devices and components in your computer work together efficiently to produce the desired result.

The two most common terms related to CD-ROM drives are average seek time and average access time. The average seek time is the time that a CD-ROM drive requires to rotate a disk. The average access time is the amount of time a CD-ROM drive requires to retrieve information from the disk. a CD-ROM drive with lower access time performs better than one having higher access time.

The following lists the average access time for different CD-ROM drives:

Type of CD-ROM Typical Access Time (in milliseconds)
1x 400
2x 300
4x 150
8x 120
10x-12x 100
16x-24x 90
32x and higher 85 or less