The development of optical drives marked a great advancement in PC technology. Before the CD-ROM drive became a ubiquitous component in PCs, users had to use install applications from 1.44MB or smaller floppy diskettes. Of course, as programs grew larger, it often took several floppies to hold them, let alone an OS (operating system) as large as Windows 95 or later. CD-ROMs can store about 650MB of information. DVD-ROMs have a minimum of 4.7GB of storage per disc. The greater storage capacities let software makers put a full program (or possibly several programs) on a single CD-ROM or DVD-ROM.

CD Drives. Today, read-only CD-ROM and DVD-ROM drives are inexpensive commodities, with many available for less than $20 online. However, we currently recommend buying a quality CD-RW (CD-rewritable) drive for less than $40 as the best balance of functions and price. A CD-RW drive can burn (write) both write-once 700MB CD-R (CD-recordable) and 640MB CD-RW discs. "Combo" drives are CD-RWs that can also read DVD-ROMs and play DVD movies.

CD drives are marked with "X" speed ratings, where 1X equals 150KB per second. For example, a 52X CD-ROM can theoretically read data at a maximum of 7,800KBps, or 7.8MBps (megabytes per second). CD-RW drive speeds are expressed in a write CD-R/rewrite CD-RW/read format, such as 52X/32X/52X. Note that some drives that can read CDs at higher speeds than 40X may actually read at 40X by default, unless the user enables faster reads by holding down the eject button for a few seconds or some other action. The reason for this is that some CD-ROM discs can't withstand 48X or 52X speeds without flying apart.

Some rewritable DVD and CD drives support the Mt. Rainier CD-RW format, also known as CD-MRW. Although Mt. Rainier is still awaiting support from Windows and other operating systems, the format promises to make CD-RWs almost as easy to use as floppies. Currently, CD-RWs require lengthy formatting and third-party software called packet-writing applications to let them accept drag-and-drop file transfers like a Zip disk or diskette. Mt. Rainier eliminates these problems with faster formatting, invisible to the user, and drag-and-drop support in the OS (still on the way at this writing). Get a jump on the future with a drive that supports Mt. Rainier.

As for blank media, be aware that some audio CD players and many CD-ROM drives cannot play or access CD-RW discs, which are reusable. CD-R, at less than 20 cents a disc in many cases, is a cheaper and more compatible option. Most stereos will play audio CD-Rs, but older players may prefer some brands over others. Newer audio CD players for home or automotive use can also play music files such as MP3s from recorded CD-R/RWs, allowing you to fit 11 or more hours of music on one disc.

Finally, don't pay extra for so-called "music" CD-Rs. They have no real advantage over "data" CD-Rs for your audio or data CD burning.

DVD drives. If you have more money to spend, a fast computer, and very large amounts of data to back up—or if you want to create your own DVD-Video discs—consider a rewritable DVD drive for $300 or less. Most new DVD burners can read and write the two major formats, DVD-RW and DVD+RW, so don't buy a single-format drive unless it's a real bargain. Both DVD-RW and DVD+RW formats currently hold 4.7GB per disc, and both have a write-once variant (DVD-R and DVD+R). Meanwhile, new DL (dual-layer) DVD drives can record 8.5GB to compatible blank media. Virtually all current DVD burners also read CD-ROMs and DVD-ROMs, as well as read and write CD-Rs and CD-RWs, so you only really need one optical drive in your PC.

DVD-RAM drives, which store 2.6GB to 9.4GB in bare discs or cartridges, are considered data backup devices, as they generally can't make DVD-Video discs. Some manufacturers now make drives that can read and write all three recordable DVD formats—DVD-RW, DVD+RW, and DVD-RAM.

Rewritable DVDs are rated on a scale nine times faster than CD drives, so 1X DVD equals 1.35MBps (1,350KBps). However, they retain the speed rating convention of write DVD±R/rewrite DVD±RW/read, as in 16X/4X/16X. A drive that can also write dual-layer DVDs or DVD-RAM will have speed ratings for burning those as well, such as 2.4X and 3X, respectively.

To play DVD movies on an older PC, you may need to install an additional card called an MPEG-2 (Moving Picture Experts Group) decoder. Newer CPUs are fast enough to decode the DVD data without a card's help. To play DVD movie discs of your own creation on a consumer DVD player, it's better to choose a newer player from a major manufacturer than to look for a particular DVD drive or brand of media. In our tests, newer consumer DVD players could play far more brands and types of DVD media than players that were just a few years old. If you want to make do with an older DVD player, the most compatible DVD formats in our tests were DVD-R, DVD+R, DVD+RW, and DVD-RW, in that order.

Internal vs. external. Most internal CD/DVD drives connect to the same EIDE (Enhanced Integrated Drive Electronics) interface as your PC's hard drive, although they technically use an interface variation called ATAPI (Advanced Technology Attachment Packet Interface). SATA (Serial Advanced Technology Attachment) optical drives are rare at this writing, but are expected to become commonplace. Try to connect an EIDE optical drive to a different data cable than the one attached to your hard drive(s).

If you want to buy an external CD/DVD drive, first check to see if your PC has Hi-Speed USB 2.0, FireWire 400, FireWire 800, or external SATA ports. Most external optical drives require one of these interfaces to reach maximum speed, although a USB 2.0 CD drive will work on a USB 1.1 port, very slowly. We don't recommend trying to burn DVDs through a USB 1.1 port.

You can add a USB 2.0, FireWire, or SATA card to most PCs to support an external CD/DVD for $50 or less. Some drives even come with adapter cards.

Final thoughts. Whichever type of CD or DVD drive you choose, it will be able to read your application and music CDs. All DVD and CD drives can read CD-ROMs, and all DVD and combo CD-RW/DVD-ROM drives can read DVD-ROMs, including DVD-Video movie discs.

A CD-RW is currently your best option under $40. However, you can find new DVD-RW/DVD+RW burners with dual-layer DVD support for less than $170 at this writing, and prices are expected to fall further.

Have fun learning to burn!