IT Certification Practice Exams

A+ Core Hardware Tutorial

DVD and DVD RW

DVD stands for Digital Video Disk (Also known as Digital Versatile Disk). Essentially, DVD looks very similar to CD-R, but contains larger storage space and can hold video, audio, and/or computer data. A single-layer, single-sided DVD has a capacity of 4.7GB where as a CD-ROM has a capacity of around 650MB. A double-layer, double-sided DVD-ROM disk can have capacity over 17GB. The DVD specification supports access rates of 600KBps to 1.3MBps.

DVD-R is a once-recordable form of DVD. DVD-RW or DVD-R/RW can be written multiple times. Many DVD drives can read data from a CD-R. But, some DVD drives may not be able to read CD-Rs. You need to ensure compatibility with CD-R when procuring a DVD drive. Normally, CD-R drives are not compatible with DVD, and you will not be able to read a DVD using a CDR.

The original speed rating for DVDs is different from that of a CD-R. For a DVD, 1x is 1352.54KB/sec. Following the convention, 2x for a DVD drive is 2,705KB/sec, 4x is 5,410KB/sec, 8x is 10,820KB/sec, and 16x would be 21,640KB/sec.

A DVD drive is shown in the figure above. It looks very similar to that of a CD drive.