Optical Drives

These days, an optical drive can be an optional part of your system or a key component in your build depending on your requirements.

On this page we’ll take a look at each of the common types of optical drives and disks such as the old CD, DVD, BD (Blu-Ray) and each of the variants such as R, RW, RAM, ROM, DL and RE.

Optical Drive
Internal optical drive for a computer


An optical drive uses a laser or visible light to read or write to optical discs such as DVDs, Blu-Ray, and CDs from your computer.

Optical drives are not required for your computer to operate, but they can provide an easy way to install programs or utilize external data that comes in disc form.

Selection Considerations

You will first want to decide if you require an optical drive at all for your PC build. Factors which may influence this decision include:

  • Frequency of optical disc use
  • Budget constraints
  • Size constraints within your case

If you do choose to invest in an optical drive, you may want to consider the following features when selecting a part:

  • Disc type and read/write compatibility
  • Speed
  • Interface (SATA, IDE, USB etc)
  • Recording performance
  • Color and style


CD – Compact Disc

These are less common these days but were the primary form of optical media for a long time. Their primary use stemmed from Audio CDs and was extended to include, PC game installation media, software installation media and general data storage / backups. You could get about 80 minutes of audio in the CDA format (this was the primary format for official high quality album releases) or about 700MB of data.


DVD – Digital Video Disc / Digital Versatile Disc

Originally designed for use as a video media this too was extended to be used for a variety of data storage purposes. The storage capacity ranges from 4.7GB to 17GB for the full 12cm disk depending on the media and technology used (see below).


BD – Blu-ray Disc

Designed to supersede DVDs for high definition video. These discs can store between 25GB to 128GB depending on the technology used.


Types of Media & Technology

ROM – Read-Only Memory

A disk containing data that can be read but not written to.


R – Recordable

A disk that can be written to once then read many times. DVDs have -R and +R, both of these are essentially the same in terms of features but are not compatible with each other. Why? Because two different companies / groups of companies couldn’t agree on a technology standard and made their own. Most DVD drives these days support both so this is typically not an issue anymore.


RW – ReWritable

A disk that be written to, read, erased and rewritten multiple times (over 1,000). Again, DVDs have a -RW and +RW version. There’s a slight difference in features here with the +RW said to be slightly more reliable.  Since they’re not compatible technologies you’ll want to make sure your drive supports both just in-case which most do these days.


RE Recordable Erasable

Exclusive to Blu-ray this disc can be written, erased and re-recorded multiple times.


RAM – Random Access Memory

Only available for DVDs, this technology is similar in nature to RW. It can be written to, read, rerased and rewritten multiple times (over 100,000). It achieves this using a different method to the -RW and +RW DVD disks and is considered to be more optimal for storing data for long periods of time (think backups) and can hold slightly more data when using dual layer disks. Again, make sure you DVD drive supports this format if you intend on using it.


DL – Dual layer

DVD-R, DVD+R and DVD+RW are available in Dual Layer. These disks utilize two recordable layers to achieve a little less than double the storage capacity. Around 8.5GB.


DS – Double Sided

Available for some of the above DVD technologies. Doubles the available capacity by adding a second side to the disk. Can sometimes be found for dual layer disks providing a total capacity (when considering both sides) of 17GB.



This essentially specifies multi-layer Blu-ray discs of up to 100GB (triple-layer) for RE discs and 128GB (quadruple-layer) for R discs.

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