Making Sense of CD–RW Drives

Interpreting the three "x" speeds

By Mark Toft
Staples Editor

A little explanation can often go a long way toward making a seemingly confusing technology product understandable. This is certainly true of CD–RW drives (also known as CD burners). With the help of this brief article, you'll be able to decipher CD–RW–drive terminology and then choose one that will best meet your needs.

Recording, rewriting, and reading speeds

All CD–RW drives prominently display three numbers followed by an "x" on their packaging. One drive on Staples.com, for instance, is the Iomega 48x12x48x CD–RW drive. What, you might ask, does that mean?

1. The first number represents the speed at which the drive records information onto a CD–R disc. A CD–R disc can have information (such as music, images, or documents) recorded to it only once.
2. The second number refers to the speed at which the drive rewrites information to a CD–RW disc. A CD–RW disc can have information recorded to it several times. CD–RW discs are often used to back up the contents of a hard drive at the end of each day or week.
3. The third number describes the speed at which the drive reads information from a compact disc. This number is at least as high as, and sometimes higher than, the recording speed. Differences in reading speeds are mainly important to people who play high–end games. High–end gamers should opt for a CD–RW drive with a reading speed of at least 40x.

What's with the "x"?

The "x" stands for 150 KBps, or kilabytes per second. To get the final recording, rewriting, and reading speeds for a CD–RW drive, you need only multiply each number by 150 KBps. Here, for instance, is a how you would calculate the respective speeds on a 48x12x48x CD–RW drive.  

Function	Speed	Total speed in kilabytes per second	Total speed in megabytes per second
Records	48 x 150 kilabytes per second	7200 KBps	7.2 MPps
Rewrites	12 x 150 kilabytes per second	1800 KBps	1.8 MPps
Reads	48 x 150 kilabytes per second	7200 KBps	7.2 MPps

Translating the numbers

The faster each speed is, the less time you'll have to wait for your CDs to be recorded, rewritten, or read. If you plan to burn a lot of audio CDs for your private music collection, you might want to pay more for a high–speed recording drive. The same goes for anyone who has to rewrite data to a CD–RW disc every day.

This table provides more concrete examples:

Sample CD–RW drive ratings	Approximate time to record a 80MB CD of music (roughly 25 songs/MP3 files)	Approximate time to rewrite a CD–RW disc containing 650MB of hard–disk back up information	How fast it reads
4x4x20x	2 minutes, 22 seconds	18 minutes	3MBps. High–end gamers will likely need a higher reading speed.*
24x10x24x	22 seconds	7 minutes, 20 seconds	3.6MBps. High–end gamers will likely need a higher reading speed.*
32x12x40x	16–17 seconds	6 minutes	6MBps. Appropriate for high–end gamers.*
48x24x48x	11 seconds	3 minutes	7.2MBps. Appropriate for high–end gamers.*
52x24x52x	10 seconds	3 minutes	7.8MBps. Appropriate for high–end gamers.*

* For specific reading speed requirements, consult the requirements listed on the box of your most important, or most often used, software.

How the drive connects to your computer

CD–RW drives are either internal or external, and almost all new computers come with one internally installed. Internal CD–RW drives connect directly to your computer's motherboard (via the IDE). As a result, internal CD–RW drives are usually faster and generally cost less than external drives.

Some people nevertheless opt for an external CD–RW drive because it's more portable, and because it doesn't require you to open your computer case and install the drive internally. External CD–RW drives can connect to your computer's USB or SCSI port. If you choose an internal CD–RW, it will include easy–to–follow installation instructions. Or, you can contact your nearest Staples store and ask whether they have a Tech Center that will, for a fee, perform the installation for you.

A word about DVD/CD-RW drives

Many CD–RW drives can also read DVD–ROM, a handy feature if you're a movie buff. Some of the latest CD–RW drives even have a DVD–RW drive. This means that the drive will not only record, rewrite, and read CDs, but it will also read, record, and rewrite DVD–R and DVD–RW discs. Since DVDs store up to 17GB of information, you'll be able to back up your entire hard drive and store movies (captured on a digital video camera), MPEG files , MP3 music files and large applications (such as PowerPoint^TM presentations, streaming videos, multimedia presentations, and CAD packages). 

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The information contained in this article is only an overview of the subject matter made for general guidance to the reader, and is subject in all cases to limitations and disclaimers set forth in Staples' Legal Terms and Conditions.

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