Stepping Up to DVD (PART ONE)
Poor, Alfred
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11/18/97
PC Magazine
Page 183
(COPYRIGHT 1997 Ziff-Davis Publishing Company) Copyright 1997 Information Access Company. All rights reserved.
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You're ready for DVD . But is it ready for you? We test six DVD -ROM upgrade kits to show you where they shine--and where they slip
The replacement of the CD-ROM has begun. DVD , the new optical-disk format, is poised to take the desktop computing and home entertainment markets by storm.
DVD disks and DVD -ROM players look much like their familiar CD counterparts, with one important advantage: Whereas a CD can hold 650MB of data, the first-generation DVD disk can store 4.7GB (4.7 gigabytes)--enough for 2 hours of quality full-motion video, with room to spare. Subsequent generations of the shiny platters promise to hold up to 17GB. Moreover, DVD -ROM players in PCs will be able to play current CD-ROM disks (though not CD-Rs in all cases, as we'll discuss later), plus the movie titles that will be released for use in home-theater DVD players in the consumer electronics area.
The Hollywood motion picture industry is behind the new media, with titles here or on the way from the collections of Columbia/TriStar, MGM, Polygram, Sony, and Warner. And in September, Disney announced that it, too, would be releasing some movies on DVD .
For computer users, however, DVD means more than just movies. The unprecedented storage capacity lets application vendors fit multiple CD titles (phone databases, map programs, encyclopedias) on a single disk, making them more convenient to use. Developers of edutainment and reference titles are also free to use video and audio clips more liberally. And game developers can script interactive games with full-motion video and surround-sound audio with less fear of running out of space. By the time you read this, more than 600 DVD movie and application titles should be ready. (For a look at five of the first ones, see the sidebar " DVD Titles: Better Games, More Data, Lots of Video.")
PCs with DVD support are already showing up on the market. And for the millions of computer owners who don't want to be left behind, vendors have rushed to offer DVD upgrade kits that end users can install on their own.
Review Criteria
For this story we tested DVD -ROM upgrade kits aimed at aftermarket buyers. Each kit had to include the drive, the MPEG-2 video decoder board needed for video playback, and all the necessary cables and instructions. Six kits--from Diamond Multimedia, Dynatek, HiVal, Pacific Digital, techmedia, and Utobia--were ready in time. Several more kits are being readied for the holiday season, chief among them offerings from Creative Labs, Panasonic, Philips, Samsung, Sony, and STB Systems.
Some users may remember the wild and woolly days of multimedia upgrade kits, when the arrival of Windows 3.0 made a CD-ROM drive and a sound card essential components of a desktop computer. That era ushered in a flood of poorly designed kits that were difficult to install and created more problems than they solved.
Our experience with the kits we tested was much better. Windows' Plug and Play does make installation easier, and these kits are much less prone to the conflicts and complications encountered with some older multimedia upgrades.
A Hard Look at Hardware
A DVD upgrade kit will set you back about the same amount as a new monitor; street prices for the kits range from $400 each (for the Diamond, techmedia, and Utobia bundles) to $700 (for the HiVal kit, which includes a wireless transmitter/receiver set to play DVD movies from your PC on a TV in another room without cables).
The bulk of the purchase price covers the hardware: a DVD drive and a decoder card. The key is the DVD drive itself. As noted earlier, DVD disks are the same size as CD-ROMs, but they can hold a lot more data. The specification was originally developed at the behest of Hollywood, which was looking for a digital way to distribute movies. The typical feature-length movie is 90 minutes or longer, and the studios wanted surround-sound audio (like that used in theaters) and the ability to have different audio tracks for different languages, as well as storage space for subtitles in different languages. The format had to support a wider aspect ratio of 16:9 (motion picture format) in addition to the 4:3 aspect ratio of traditional televisions and computer monitors.
These requirements added up to the need for more storage capacity on a disk--lots more of it. The 650MB capacity of a CD-ROM is sufficient to hold only about 75 minutes of stereo sound--not enough for the sound track of a full-length movie, let alone the images.
By designing the disk drive with a laser using a shorter wavelength, engineers were able to move the data tracks closer together on a DVD disk than on a CD-ROM and to squeeze more data into a given length of track. As a result, a DVD disk can hold as much as 4.7GB of data on one side. The specification also calls for dual-layer disks that can hold 8.5GB per side. The DVD specification also includes "flippy" disks, which are recorded on both sides and will eventually hold a whopping 17GB.
For theater-like sound, the DVD specification calls for the use of Dolby Digital sound (sometimes referred to as AC-3), which is also known as 5.1-channel sound. This provides left, right, and center front channels plus separate left and right rear effects channels (requiring five speakers in all), plus a subwoofer signal (the ".1" in 5.1). Movies that have been dubbed in other languages are mixed so the dialog is in the center channel. Change the language and a different sound track plays for just that channel; the sound effects and musical score remain unchanged.
A short bit on compression
The 4.7GB capacity may seem like an enormous amount, but it's still too small to fit a full movie of digitized images and sound without data compression. DVD uses MPEG-2 compression (from the Motion Picture Experts Group) for the video, and Dolby Digital compression for the audio (though European titles will use MPEG-2's audio compression scheme).
This data must be decompressed before it can be used. Your computer's CPU can perform the calculations required, but not fast enough to keep pace with the images and sounds and have cycles left for its other tasks, too. So a DVD upgrade kit adds a decoder board to the DVD drive. The decoder board processes the data stream as it's received from the DVD drive and sends out the images and sounds to your PC's graphics subsystem (or directly to the screen) and to its sound system.
The features that make DVD perfect for watching movies at home make them irresistible for computer use. In addition to the increased capacity, performance is also impressive: The first generation of DVD drives are able to read data at 1,350 KBps (kilobytes per second)--roughly the equivalent of 8X CD-ROM drives. Such speed makes it tempting to swap your existing CD-ROM drive for a DVD solution.
Too soon?
Is it too soon to upgrade your system to DVD ? There are a number of developments that may encourage some users to wait before taking the plunge.
If you intend to use the system for data access--for instance, using DVD -ROM reference titles--you may want to wait for kits that include the next generation of DVD drives. Existing drives are fast, but there are already faster drives arriving on the market that claim 16X speed for DVD and 20X throughput in CD-ROM mode (versus the current 8X CD-ROM speed).
Another reason to avoid the first generation of drives is that although they can read mass-produced CD-ROMs, most drives cannot read the custom-burned CD-R (compact disk-recordable) disks, which are becoming more prevalent in the corporate world. On our tests, the one kit that could read CD-R (the Hitachi drive in the Pacific Digital kit) could not read all CD-R media. The next drives are expected to support all CD formats, including CD-R and CD-RW (compact disk-rewritable).
In fact, you may not want to get a DVD -ROM drive at all. Like CD-ROM, today's DVD is a read-only format. The first read/write/erasable DVD drives--called DVD -RAM--are expected to be on the market around the first of the year. Compatible with all CD formats and DVD -ROM disks, these drives will also provide large-capacity storage (2.6GB) for backup and archival purposes. Thus, a single device could serve many functions.
War of the Acronyms
At this point, the crystal ball is cloudy about the rewritable DVD market segment. The DVD Forum (the association formerly known as the DVD Consortium, the group of companies that originally developed the DVD specification) agreed on a DVD -RAM specification that used phase-change technology to reach a 2.6GB capacity per side.
Then a group of six companies--Hewlett-Packard, Mitsubishi, Philips, Ricoh, Sony, and Yamaha--broke ranks to create the Phase-Change Rewritable (DVD+RW) specification, which offers a 3GB capacity. And NEC weighed in with its own Multimedia Video File (MMVF) format, with a 5.2GB capacity per side. Although it is too soon to know for certain, it appears that these new specifications are designed so that existing DVD -ROM drives will be able to read both DVD+RW and MMVF disks as if they were standard DVD disks.
And if this weren't enough, Digital Video Express has announced a new format of movie disk for the home entertainment market. The Divx is a one-use disk incompatible with set-top home DVD players, though Divx players will play DVD movies.
Then there is the question of Windows 98. This operating system will reportedly provide system-level support for both DVD drives and decoder cards, besides including software for DVD navigation. But until Windows 98 ships, DVD upgrade kits will have to include manufacturer-provided drivers and software.
All-in-one decoders coming, too
Perhaps the biggest reason to wait, however, is for the next versions of the decoder cards. There are new decoder chips on the way (such as the DVDPC LS220 from LuxSonor) that integrate all functions on a single chip: MPEG-2 decoding, Dolby Digital decoding, video and audio interface, and even DVD copy-protection support. Some chips (like Chromatic Research's Mpact/3600 media processor chip) are programmable, so features can be added on the fly.
Chips like these will make it easier to integrate the graphics and DVD functions onto a single expansion board that can replace an existing graphics adapter, so you won't need two cards. All the designs in this roundup rely on an analog-overlay design, which means that the graphics card has to leave a hole in what it displays to leave a space where the DVD image appears. This requires careful synchronizing of the signals between the DVD decoder card and the existing graphics card. Also, either the graphics signal has to be looped through to the decoder card or the DVD image must be sent across the PCI data bus to the graphics card. Both strategies have performance and quality drawbacks.
Putting all the functions on a single card means that the graphics processor and the decoder can write to the same shared video-buffer memory. This will improve playback image quality and performance. There are even chips that can handle all the decoder and graphics-processing functions, eliminating the need to have different subsystems handled by different chips on the board. The first boards of this type are expected to reach the market by the time this is in print; you can expect to see them in new computer systems first, because they will save a slot for DVD -enabled configurations. As an upgrade, this approach requires the user to replace the graphics adapter, so there may be a longer delay before this type of hardware finds its way into the upgrade market.
In spite of similarities and in some cases the same components, each kit in this roundup has a different set of features and flaws. If you're itching to have the latest technology on your desktop or to create an awesome home-theater installation driven by a PC, you'll find some passable but not perfect candidates among these six. Then all you need is the popcorn, and you can stay home to watch the movies.
Are any of these kits right for you, or are you better off waiting for the latest DVD -ROM solutions? Visit the interactive version of this story and see for yourself.
Our Contributors: ALFRED POOR and JAN OZER are contributing editors of PC Magazine. JAMES KARNEY is a frequent contributor to the magazine. JAMIE M. BSALES was the editor in charge of this story, and JEFF MACE was the project leader.
Editors' Choice
Close, but not there yet
These first-generation DVD upgrade kits all fall short of the mark for one reason or another. We would wait for the next generation.
Each of the kits in this roundup is based on an analog-overlay design to put the DVD image on a computer screen. Although this design would be fine for television output, the quality and performance on computer displays could be improved. If you want to watch movies on your computer screen, wait for a kit with an integrated graphics card or one that uses the VGA feature connector to tie the MPEG-decoded image right into the graphics card's buffer memory. Also, most of these kits rely on first-generation DVD drives. Only the Pacific Digital DVD -ROM Kit ($550 street) could read CD-R disks. If you're going to be replacing your CD-ROM with a DVD drive, you'll need to wait a little longer before you can count on the replacement to read everything.
If you want to take the plunge now, however, consider the Diamond Maximum DVD Kit ($400 street). It was easy to install and delivers a wealth of DVD titles. Videophiles might consider the Utobia Hollywood DVD /MPEG-2 AC-3 Playback Kit ($400 street), which delivered the best video playback quality thanks to its Sigma Designs MPEG-2 decoder chip. A scant bundle, poor documentation, and lack of Dolby Digital audio support are the kit's drawbacks. |
