Building a Computer for A+ Study Part VI: The Optical Drive

Part six in a series on the basics of building a computer to prepare for the A+ certification exams.

The Optical Drive

An optical drive, also known as an optical disk drive (ODD), reads and writes data from optical disks using laser beaming technology. Optical drives work by rotating the inserted disk at a constant speed, which is calculated in revolutions per minute (RPM). The rotating disk in an optical drive utilizes the lasers to read data from, or write data to, CD (Compact Disc), DVD (Digital Versatile Disc) or BD (Blu-ray Disc). While optical drives can spin discs at very high speeds, they are still significantly slower than hard drives. The back end of the optical drive contains a port for a cable that connects to the motherboard. An internal optical drive can interface with the motherboard using an PATA (IDE) or SATA connection.

Optical Drive Media

While media for an optical drive consist of 120 mm (12 cm) diameter discs, they can come in different formats so it is important to know which formats the optical drive you purchase will support. Popular optical drive formats include CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-R DL, DVD+R DL, BD-R, and BD-RE.
The writing of data to a disc is called burning. Read only media (ROM), such as in CD-ROMs or DVD-ROMs, do not allow anything to be written to to the media, only reads it. Media that you are able to write to has either a -R, -RW, +R, +RW, or -RE after the type of disc (‘R’ means that the disc is Recordable, ‘RW’ means that the disc is Rewritable and ‘RE’, which is only used with Blu-ray discs, means that it is Recordable Erasable).
A standard CD can hold between 650MB and 700MB of data on it. While data is written to only one side of a CD, data can be written to either one or both sides of DVD and BD discs. DVDs and BDs can be any combination of single and double sides and layers, which determines the amount of data that can be stored on a single disc.
  • Single-sided, single-layer DVD can hold 4.7GB of data
  • Single-sided, dual-layer DVD can hold 8.5GB of data
  • Double-sided, single-layer DVD can hold 9.4GB of data
  • Double-sided, dual-layer DVD can hold 15.9GB of data
  • Double-sided, single-layer BD can hold 25GB of data
  • Double-sided, dual-layer BD can hold 50GB of data
It is also worth noting that recordable discs also come in different speed ratings. The speed ratings of blank discs should match the speed ratings of the optical drives because you’ll get the best results by using discs that are rated at or above the speed of your drive. For example, if you have a 8x drive, you should use 8x or faster discs. Matching the speed rating of the disc to the speed rating you burn at will give the best results.

What I Picked

I chose the Lite-On iHAS124-04 DVD burner. It enables users to burn any DVD+R/-R, DVD+RW/-RW disc and supports the dual-layer function allowing up to 8.5GB data to be burned and saved on a single dual-layer disc. The speeds for reading and writing to the different are as follows: 24X DVD+R, 8X DVD+RW,  12X DVD+R DL,  24X DVD-R, 6X DVD-RW, 16X DVD-ROM, 48X CD-R, 32X CD-RW, 48X CD-ROM.
The decision to include an optical drive as you are building your computer is based on your own personal needs. Because a large majority of software is downloadable or can be saved onto USB flash drives, optical drives are becoming obsolete. However, since optical drives are relatively cheap these days it does not hurt to install one especially if you will have a bunch of installation discs to use.

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