PC-DVD kits reviewed.......................
Go to the link to see the individual reviews. No second generation kits.
zdnet.com
Seven DVD-ROM Upgrade Kits
Hasten the Digital
Revolution
by Matthew Klare
Originally published in the December 1997
issue
Some border disputes have evoked less
hostility than the development of DVD and have
been resolved with less political maneuvering.
Indeed, at times, it seemed as though DVD
would provide a textbook example of
competing interests stopping a promising
technology dead in its tracks.
This would-be successor to CD-Audio,
CD-ROM, laserdisc, and even VHS
technologies resulted from the unification of two
initially separate efforts: one by CD developers
Sony and Philips Electronics and another led by
Toshiba. The new technology gained plenty of
attention early in its development largely
because of its luxurious capacity--4.7GB for a
single-layer, single-sided disc and 8.5GB for a
dual-layer, single-sided disc. Double-sided discs increase capacity to 9.4GB
for single-layer media and 17GB for dual- layer media. CD-ROM looks
decidedly anemic in comparison, with its maximum capacity of 650MB.
Cross-industry compatibility and potential for cross-industry innovation are
among its greatest advantages, but they also pose serious threats to DVD's
survival. Just as a CD-ROM drive lets you play audio CDs on your
computer, a DVD-ROM drive paired with the appropriate DVD decoding
capabilities--necessary for translating the MPEG-2 video stream and Dolby
AC-3 Digital Surround Sound--lets you play DVD-Video titles at your desk.
Keep in mind that you'll need either Dolby Pro Logic speakers, an outboard
sound processor, or an AC-3-capable stereo receiver to extract the surround
sound. Otherwise, you get just basic two-channel stereo.
The digital nature of DVD helps give the concept of the living-room PC at
least a fighting chance: A living-room PC could handle the decoding required
to play DVD-Video titles just as well as a stand-alone DVD-Video player.
Plus, it would offer other features a dedicated DVD-Video player couldn't,
such as the ability to browse the Internet or play 3-D games. But because
digital content can be copied with no loss in quality--unlike copies to or from
analog VHS tapes--Hollywood balked at the idea of millions of computer
users having access to unprotected digital copies of its expensive works. The
movie studios insisted that a robust copy-protection mechanism be put in
place, and a long standoff ensued between the computer industry and the
studios over the nature of the copy protection and other issues. Hollywood
largely got its way, so prepare for disappointment if you had hoped to patch
together a happier ending for your favorite flick. A multilayer copy-protection
scheme ensures that none but the most obsessively determined and
unproductively ingenious individual will be able to copy any portion of a
DVD-Video title.
Happily, DVD survived. Indeed, at press time, DVD-Video titles from
several major studios became available nationwide, emerging from their
seven-city introductory market. And as the seven upgrade kits reviewed in the
following pages attest, DVD-ROM is also alive and well, if still in its infancy.
These first-generation upgrade kits have their share of rough edges, but even
so, they crank out MPEG-2 video and Dolby Surround-Sound audio better
than any other reasonably priced hardware you can currently find for your
PC.
DVD Differences
For this roundup, we requested DVD upgrade kits that included a
DVD-ROM drive and a board that could decode DVD-Video title MPEG-2
video.
The seven upgrade kits we tested here range in price from $400 direct for the
Diamond Maximum DVD Kit to $899 average by mail for the Hi-Val DVD
PC to TV Home Entertainment System. But the average for the group is only
$573. The Hi-Val kit ranks as the most expensive by far because it includes a
radio-frequency (RF) broadcast system, which adds nearly $300 to its price.
The important differences among these kits begin with the DVD-ROM drive
they use. Each of the seven kits has one of three drives, manu- factured by
Hitachi, Pioneer, and Toshiba. All three can read single- and double-layer
DVD discs, and handle most types of discs that your current CD-ROM drive
can read, including CD-ROM discs and audio CDs. Of the three, however,
only the Hitachi drive can read CD-R and CD-RW discs, thanks to its
inclusion of an additional 780nm laser.
While a 1x CD-ROM drive has a maximum data rate of only 150K/sec, a 1x
DVD-ROM drive can dish out data at 1,250K/sec, which is just over the
speed of an 8x CD-ROM drive. Surprisingly, although the Pioneer and
Toshiba drives use 1x mechanisms, Hitachi has already made the jump to 2x.
The Hitachi drive's faster spin rates won't improve DVD-Video playback--all
the drives tested here can keep MPEG-2 video streaming from discs at
sufficient speeds. However, the rates will improve performance with
DVD-ROM titles at least in some circumstances, such as when reading new
scenes to memory or a hard drive.
The three drives used by these kits also differ in CD-ROM performance. All
three spin at a constant linear velocity (CLV) when functioning in DVD
modes: They vary rotational speed to keep data flowing past the laser at a
constant rate. But they use a variety of approaches when reading CD-ROMs.
The Toshiba drive subscribes to the tried-and-true CLV method, delivering a
constant 8x CD-ROM throughput. To improve both CD-ROM access time
and maximum throughput, the Hitachi maintains a constant angular velocity
(CAV), providing 8x to 20x CD-ROM throughput. The Pioneer employs
partial CAV (pCAV), which uses CAV near the inner portion of the disc and
CLV near the outer. Its CD-ROM throughput ranges from about 8x to 10x.
The Decoder Choice
The decoder boards packaged with the upgrade kits in this roundup use one
of two strategies for delivering MPEG-2 video. The board in the Diamond kit
and the Sigma Designs RealMagic Hollywood board in the Utobia kit use a
technique called analog overlay, also referred to as video overlay or simply
overlay. The five kits using Quadrant International's Cine- Master board
employ the VGA-inlay approach, which Quadrant refers to as VideoInlay.
Both methods display video in a window or at full screen, but they take
different approaches. VideoInlay relies on your PC's graphics adapter to
scale the video and output it to your monitor. In contrast, the overlay boards
provide their own hardware scaling and output the video themselves,
overlaying it with graphics output passed through from your VGA card. With
these boards, an included cable runs from the VGA connect of your display
adapter to an input on the bracket of the decoder board.
The major drawback of the CineMaster's approach is the load it places on
your system. While pushing 30 frames of video per second might not saturate
the PCI bus, it does keep bus utilization high. When playing scenes encoded
at a high bit rate, the CineMaster boards tended to overwhelm most display
adapters with too much data. To get an acceptable picture with some cards,
we had to reduce the maximum number of horizontal pixels displayed from
720 to about 535.
Before buying a VGA-inlay-based card, check with the manufacturer of the
upgrade kit or decoder board to ensure that your display adapter will be able
to handle the load. As we worked on this article, the CineMaster boards
reported compatibility with the following chip sets: ATI Technologies' Mach
64 and Rage 2+; Matrox Graphics' MGA chip sets; Number Nine Visual
Technology's Imagine and Imagine II; S3's Vision 868, Vision 968,
Virge/DX, Virge/VX, and Trio 64 II; and Tseng Labs ET6000. We used an
ATI Xpert@Play VGA card in the subjective DVD-Video testing. Note that
even if your display adapter uses one of these chip sets, you may still have to
lower video quality to get a stable image.
Requiring a bit more work to install and configure than VGA-inlay boards,
video-overlay boards also demand less of your system and tolerate a wider
variety of hardware. You should be able to use nearly any video card with
these boards and still achieve decent performance. The video output of the
two overlay solutions tested wasn't as sharp as that displayed by the
VGA-inlay boards. Then again, unless you're already accustomed to watching
movies played by a living-room DVD player, you probably wouldn't notice
the difference.
As usual, don't forget to check out the software bundled with each product as
you narrow your choices. Some kits provide several DVD-ROM titles and
even a DVD-Video sampler or two; others provide none. Also keep the
supplied DVD utilities in mind. These utilities are linked to the decoder board
used in a system. So while the Diamond and Utobia kits provide their own
utilities, the five CineMaster-based kits use the same Quadrant International
utilities.
Finally, to deliver the best MPEG-2 video and AC-3 audio simultaneously,
you'll probably need at least a 133MHz Pentium system with at least 16MB
of RAM. And here, we subscribe to the more-is-better theory. Particularly if
you opt for a CineMaster-based kit, the more horsepower the PC has, the
happier you'll probably be with its performance. |
