How to buy ... a DVD Rewritable Drive

A rewritable DVD drive lets you store far more data on a single DVD disc than you could store on a single CD-R disc. Single-layer media lets you store up to 4.7GB on a disc, while dual-layer (also referred to as double-layer) media lets you pack up to 8.5GB on a single disc. Like CD-RW drives, rewritable DVD drives support both write-once and rewritable media; the former is best used for creating DVD-Video discs playable on standard DVD players and for data archiving, while the latter is well suited for regular file backup.

The Big Picture

DVD burners are now as mainstream as CD writers--and no wonder: The average price of a drive keeps dropping, with prices starting as low as $80 retail. The format wars are a distant memory now; drives typically support writing to and reading from both of the competing, incompatible disc formats -- DVD-RW and DVD+RW (and their corresponding write-once variants, DVD-R and DVD+R). Both formats burn data and video DVDs that can be read by many (but not all) DVD-ROM drives and television set-top DVD players. Increasingly, we're seeing so-called Super-Multi drives, which can record to a third format, DVD-RAM, as well. DVD-RAM lags behind the + and - formats, hindered by its playback incompatibility with most DVD-ROM drives and set-top DVD players.

Blu-ray and HD-DVD: Unless you've been living under a rock, you'll know there is a next-generation optical format war going on. Blu-ray and HD-DVD both offer hugely increased storage capacity on discs and this has significant appeal, especially when it comes to high-definition video. About four hours of 1080p high-def video will fit on a 50GB disc. However, this war is far from won and in terms of writable drives for computers there is very little to choose from. Sony is selling an internal Blu-ray drive for $2000 that will write to 25GB and 50GB Blu-ray discs at a maximum speed of 2x. The drive will also write to all DVD media formats as well as CD-Rs. However, any Blu-ray disc you burn will only play on a Blu-ray player or drive, not a standard DVD player or drive. HD-DVD writable drives are rumoured but none have so far surfaced. Best to wait unless you must be on the bleeding edge of technology.

Key Features

Write-once DVD: Because write-once DVD-R and DVD+R media have a highly reflective backing, they offer the best compatibility with set-top DVD players, though some players are more sensitive to a disc's reflectivity than others. Currently, the fastest write speed is 16X for recording on single-layer DVD-R and DVD+R media; 18X is due by the end of 2006, but don't expect to see like-rated media to use with these drives. Double-layer DVD+R media and dual-layer DVD-R media are both rated at 8X.

Accordingly, single-layer write-once media is usually the best choice for archiving data or for burning video DVDs you want to view on your living room player. You can buy the discs everywhere from drugstores to electronics stores. Such DVD-R and DVD+R discs are least expensive when purchased in spindles--you can find spindles of 100 discs for as little as $1per disc. Industry experts estimate that write-once media is compatible with at least 85% of set-top players; that number climbs even higher when you look at the latest generation of players.

Rewritable DVD: Rewritable formats include DVD-RW, DVD+RW, and DVD-RAM. DVD-RAM is the least compatible of the three, but its robust error correction and high rewrite rating (vendors claim discs can be written to up to 100,000 times, compared with 1000 times for -RW and +RW media) make it a good choice for data backup. Drives generally support bare-disc DVD-RAM media; cartridge media is still available, but few drives support it (such media is contained within a protective enclosure about the size of a jewel case).

The current speeds for rewritable media max out at 12X for DVD-RAM, 8X for DVD+RW, and 6X for DVD-RW. Industry experts estimate that DVD+RW and DVD-RW discs are compatible with about 60% of the installed base of DVD players and drives. By contrast, only other DVD-RAM drives and a handful of DVD-ROM drives can read DVD-RAM discs.

Rewritable media tends to be more expensive than write-once media; you can expect discs to cost from approximately $2 a piece.

Internal versus external drives: Internal DVD burners, whether they use the older IDE connectors or newer SATA connections (still uncommon on burners), cost less than external models, by as much as $100 or more. External drives typically use either the FireWire (IEEE 1394) or USB 2.0 interface; some drive manufacturers offer both connectors on the same drive.

CD-R/RW recording: All rewritable DVD drives can burn CD-R and CD-RW discs. DVD drives typically burn CD-Rs at speeds of 40X to 52X; dedicated CD-R writers max out at 52X. CD-RW write speeds are comparable to those found on stand-alone CD writers as well.

Software bundle: All drives packaged for retail include video DVD authoring software that allows you to create menus and encode analogue video to MPEG-2 so that you can play the resulting video DVD on a standard DVD set-top player. In addition, all drives can create data DVDs with their bundled mastering and packet-writing software. The most common software bundles include various versions of Nero's Nero Express 6.6 and Roxio's Easy Media Creator 7.5.

Beware of a drive sold at a low cost and without any software. This drive is probably intended for sale as a "bare" OEM drive, which means that it comes without software, and often without a warranty and the necessary firmware updates that are standard with drives sold at retail.

LightScribe: Many drives now support LightScribe, a disc-etching technology licensed by Hewlett-Packard. Often, you won't pay a significant premium for a drive with LightScribe support; however, LightScribe-enabled drives sometimes don't support the latest and greatest disc -write speeds. If speed is important to you, check the drive's specs.

With a LightScribe drive and specially coated LightScribe media, you can flip the disc over and use the drive's laser to etch a monochromatic label--as elaborate or as simple as you want--on the disc's top surface. It can take 20 minutes or more to etch a complex, full-surface label.

The Specs Explained

DVD-Rewritable drive specifications are expressed in a confusing litany of numbers and letters. We'll try to decipher them for you here and let you know which we consider important, somewhat important, or minor in a buying decision.

Important: Disc Formats
DVD burners today can write and rewrite to a variety of disc formats. What all the formats mean and how to distinguish among them are the primary questions facing prospective buyers. Most DVD burners can write to both write-once (R) and rewritable (RW) media. Each type of media comes in two formats: DVD+R and DVD-R; and DVD+RW and DVD-RW. You'll want a DVD burner that supports both + and - formats for maximum compatibility.

A growing number of DVD burners can write to both single-layer and dual-layer (or double-layer) formats. Single-layer discs hold 4.7GB of data. Dual- or double-layer discs hold 9GB of data.

Write-once DVD -- which encompasses both DVD-R and DVD+R -- is the most compatible DVD format, especially for sharing discs with living room DVD players. DVD-R SL and DL (single-layer and dual-layer) and DVD+R SL and DL (single-layer and double-layer) are the four write-once variants.

DVD-RW, DVD+RW, and DVD-RAM are three rewritable variants you might encounter. Be sure not to buy one of the older, first-generation DVD+RW burners that lack write-once DVD.

Important: Write-Once DVD Speeds
Speed is becoming a bigger issue now that there are both DVD-R and DVD+R drives available that support writing at 8X. Following are the current maximum speed ratings: 16X for DVD-R SL and DVD+R SL; 6X for DVD-R DL; 8X for DVD+R DL; 2.4X to 12X for DVD+RW; 1X to 8X for DVD-R; and 4X to 8X for DVD+R.

Important: Rewritable-DVD Speeds
DVD-RW and DVD+RW are about equally compatible with most DVD drives and DVD players. But DVD-RW usually takes longer to format than DVD+RW. DVD-RAM's higher rewrite rating -- up to 100,000 rewrites, compared with up to 1000 for DVD-RW and +RW -- and robust error correction capabilities make this a good format for data. However, DVD-RAM is less compatible with other DVD drives and players.

Currently, the maximum write speeds are 6X for DVD-RW, 8X for DVD+RW, and 12X for DVD-RAM.

Somewhat Important: Interface
Internal drives -- as with other storage devices -- tend to be cheaper than external ones. If you're buying an external drive, pick an external drive interface that matches what's installed on your system -- or pick a drive that supports both FireWire and USB 2.0 for maximum flexibility.

Somewhat Important: Software
If you know how you plan to use your drive, you may get a better deal if the drive includes the software you'll need. Check to see how complete the OEM bundle of the burning software (such as Roxio's Easy Media Creator or Nero's Nero Express) is; also, see if the burner includes backup software or additional video or image editing software.

Rewritable DVD Shopping Tips

Are you ready to buy a rewritable DVD drive? Here are PC World's recommendations for buying a drive that will best suit the needs of the average user.

Decide if speed is important to you. At this writing, speed is not much of an issue, since the two write-once/single-layer DVD formats are identical. Keep an eye on double/dual-layer write speeds, though--many drives on the market don't support the fastest speeds possible.

Consider compatibility. Both DVD-R and DVD+R are highly compatible with current DVD players and DVD-ROM drives. Some older players might have better luck with DVD-R than DVD+R, simply because DVD-R has been around longer. Beware of DVD-RAM: The format can be useful, but it's poorly suited to burning to discs you plan to share with friends and family.

For desktop PCs, get an internal drive with an IDE interface. Since a rewritable DVD drive can read DVD-ROMs and CDs, and write to CD-R/RW, you can replace your existing CD-ROM, DVD-ROM, or even CD-RW drive without sacrificing functionality.

For external drives, or desktop PCs with few internal connections, consider the interface. With external drives, you'll see about the same speed from a FireWire drive as you would from a USB 2.0 drive. Costs for drives of each interface type are similar, and for a few more dollars, you can often buy a drive that has the flexibility of both interfaces. To use a FireWire or USB 2.0 drive, you may need to buy a USB 2.0 or FireWire card for your PC, but on some desktops having such a card can make it easier for a rewritable DVD drive to coexist with multiple hard drives and/or other optical drives.

Make sure that the bundled recording software fits your needs. All manufacturers provide software with drives sold at retail; the software typically covers DVD and CD mastering (including audio CDs), DVD video authoring, and the ability to drag and drop data. However, some vendors also add software for backup tasks and video editing.