But you need a fast PC for best results with these four new units
Michael Nadeau
The standard-issue double-speed CD-ROM drives found on most PCs today are no longer good enough to play back multimedia software. They simply can't read and send the data fast enough to the computer's processor, graphics accelerator, and sound card to maintain smooth, uninterrupted operation. In business, this is a serious issue. Jerky video and choppy audio can destroy an otherwise strong presentation or diminish the effectiveness of a training film.
Quad-speed drives
, which spin at twice the rate of double-speed CD-ROM drives, have been available for several years, but only as bulky external units and at high prices. Four companies--TEAC, Plextor, NEC Technologies, and Toshiba-
-recently introduced quad-speed drives priced from around $475 for some internal models to as high as $775 for external drives. Although you still pay significantly more than you would for most double-speed models, these drives are well worth the price--as long as you install them in a PC that is properly equipped to handle them.
Just because the data access rate of a quad-speed drive is twice that of a double-speed unit (600 KBps vs. 300 KBps) doesn't mean that you will see a doubling in performance. The truest measure of multimedia playback performance is the throughput to the video display or other output device, and that depends a great deal on the computer's processor and graphics accelerator. If one or both are too slow, the quad-speed drive will be in a hurry-up-and-wait mode much of the time. This is especially true for CD-ROM drives with large, intelligent caches. A quad-speed drive will provide better throughput on nearly any PC, but to get your money's worth, you need to install it in at lea
st a 50-MHz 486DX2 system with a 64-bit local-bus graphics accelerator card.
Another consideration: Your system can play back video no faster than the data rate at which it was recorded. To accommodate single-speed models, the lowest common denominator among CD-ROM drives, the video for most commercial titles is recorded at a rate of about 150 KBps. A higher data rate will improve the video quality, but if you play back that video on a drive that's slower than the rate at which the video was recorded, you will get a slow, jerky mess. By the end of this year, quad-speed drives are expected to become the unit of choice, and software developers are just now beginning to optimize video for quad-speed drives.
Four Quads
The four drives I tested were the NEC MultiSpin 4Xe Model CDR-601K, Plextor 4Plex PX-43CH, TEAC SuperQuad Model CD-55A, and Toshiba XM-3501B. All the drives are half-height or smaller and come with a suite of software that includes drivers for DOS and Windows, a
utility for playing audio CDs, and installation software. You can also buy external Mac versions of all but the TEAC drive. Each of the drives has a headphone jack and an audio-line-out connector for use with sound boards. All review units except for the NEC were internal drives.
Compared to NEC's MultiSpin 4X Pro, introduced in 1994, the new 4Xi and 4Xe drives offer less in the way of performance and features but cost almost $200 less. However, the external NEC MultiSpin 4Xe ($515 without adapter) is still feature-rich. It automatically senses audio CDs and plays them as such when you insert them. Standard audio CD controls are on the front panel. Audio capability is built into the drive unit, so you don't need to have a sound board in your PC. You will need speakers, however. An EPP (enhanced parallel-port) connector on the back of the unit lets you use the unit with EPP-equipped portables, providing a theoretical 1-MB-per-second transfer rate. A lens-cleaning system inside the unit keeps the dust t
hat gets by the 4Xe's double dust door from interfering with disc reads. NEC supplied a 16-bit Trantor ISA SCSI-2 adapter and its own drivers. The 4Xe was the only unit to come bundled with CD-ROM titles: Microsoft Encarta and NEC's CD Tutorial. An internal unit, the 4Xi, is also available ($415 without adapter).
The Plextor 4Plex PX-43CH ($489 without adapter) came with a Future Domain TMC 1610 16-bit SCSI-2 ISA adapter. It differs from the Future Domain adapter used by Toshiba only in that it has its own ROM BIOS. Plextor, like the vendors of other drives reviewed, offers several adapter options, or it will sell the unit without one. The drivers supplied were based on Corel's PowerSCSI product. At 1 MB, the Plextor drive has the largest built-in cache. The external 4Plex PX-43CH goes for $599 without an adapter.
TEAC's SuperQuad is unique among the group not only because of its slim 1-inch-high profile, but also because it uses a motorized tray rather than a separate disc caddy. It is also the
only drive that isn't a SCSI device. TEAC uses Creative Lab's proprietary version of the AT interface (aka IDE), which works with Sound Blaster cards. The others use SCSI adapters. In spite of the AT interface, the TEAC drive doesn't have a price advantage ($599 with interface card). Because of its AT interface, the TEAC is the only drive that doesn't come in a external model, but it was the simplest internal unit to get up and running. The adapter has no jumpers or DIP switches to set, and if you wish, you can run the drive off a sound card. I tested the TEAC unit running from the included AT adapter and from a Sound Blaster 16 sound card and found only minimal performance differences.
Toshiba offers three models of the XM-3501. I tested the internal XM-3501B ($470 without adapter). The TXM-3501E ($600 without adapter) is the external version, and the TXM-3501A4 ($2470) is a four-drive unit. All can be mounted horizontally, vertically, or even diagonally. Toshiba supplied a Future Domain TMC1610-MEX,
16-bit SCSI-2 ISA adapter that uses Toshiba's own drivers.
How I Tested
I ran three sets of benchmark tests on the four drives on a Dell Dimension 466V with a 66-MHz 486DX2 CPU, a 64-bit Number Nine ##9GXE64 VL-Bus graphics accelerator, and a Creative Labs Sound Blaster 16 audio card. For comparison, I also ran all tests on the CD-ROM drive that came with the Dell, a double-speed Matsushita Model CR-563-B (see the benchmark tables, "
Quad-Speed Performance -- Part I
" and "
Quad-Speed Performance -- Part II
").
The first set was a suite of low-level tests called CDStone (version 1.1), which was developed by The Profit Group (Tucson, AZ). It measures seek time across the entire width of the disc (full stroke), across one-third of the disc (one-third stroke), and across random distances. A good full-stroke score indicates that the drive can locate a specific track more quickly. The one-third stroke test is most commonly use
d as a standard means of rating the seek times of CD-ROM drives. The random-distance test more closely represents real-world circumstances.
CDStone also measures the read rate for both large and small blocks of data. A good score on the large-block read test is an indicator that the drive can handle video and audio files well, and the small-block test reflects a drive's likely performance with database or other text files. Finally, CDStone measures CPU use during data access at 150 KBps and 300 KBps. CDStone then provides an overall index of performance, using a typical single-speed drive as the baseline.
The second test suite consists of three well-known animation files--Robo Truck, Roller Coaster/Mount St. Helens, and AutoDesk Building--that were created using AutoCAD. The scores are simply the number of seconds each required to complete each animation.
The last suite was meant to separate the wheat from the chaff. It consisted of four versions of the same video file: an Intel TV ad. Al
l four ran using Video for Windows. Three used Cinepak video compression but were recorded at different data rates: 150 KBps, 300 KBps, and 600 KBps. The last version was recorded at 475 KBps, using Indeo compression, which is much more CPU-intensive. I used the Intel ad because it was available at the higher data rates.
Remember, most commercial CD-ROM video is recorded at lower rates. While a good double-speed drive should be able to play back a clip recorded at 300 KBps, it will choke on anything recorded at a higher rate. On the other hand, video recorded at 300 KBps or lower presents no challenge at all to a quad-speed drive.
Head-to-Head
I evaluated each unit for ease of installation, performance, and value. Installing each drive was a snap. The external NEC unit was, of course, the easiest to install: I simply inserted the adapter and plugged in the power and SCSI cables. After mounting the internal units, I plugged in the power, SCSI or AT, and sound cables. Only
one snag arose: The Plextor drive had a different sound cable connector from the one that came with the Sound Blaster board.
Loading the drivers had greater potential for presenting problems, but surprisingly, driver installation was successful on the first try on three of the four units. The PowerSCSI drivers that came with the Plextor's Future Domain adapter didn't get along with the driver for the Number Nine graphics accelerator. After trying various settings, I got the two working together, but only by disabling Microsoft's EMM386 memory manager as well. If you want to use the Plextor drive with the ##9GXE64, check with Future Domain and Number Nine first to see if they have updated their drivers, or use a different SCSI adapter.
All the vendors hype their drives' 600-KBps transfer rates and low average seek times, but I found seek time ratings a poor indicator of overall CD-ROM drive performance. The tests placed the Toshiba and Plextor drives almost even at the top, with a slight edge to
Plextor. On the low-level CDStone and 600-KBps video tests, both drives were almost twice as fast as the double-speed Matsushita drive. The Toshiba and Plextor were about 45 percent faster than the double-speed drive on the animation tests, and about 14 percent faster on the Indeo video test. Every drive tested ran the 150-KBps and 300-KBps video tests at the full 30 frame-per-second rate, and every quad-speed drive except the TEAC also ran the 600-KBps video test at the full frame rate.
In the CDStone and AutoCAD animation tests, the NEC unit ran 3 percent to 9 percent behind the leaders; it was about 9 percent slower than the Plextor on the Indeo video test, for example. The TEAC drive brought up the rear. To keep things in perspective, however, keep in mind that all the quad-speed drives blow the doors off even the best double-speed units available. The TEAC, slowest of the bunch, was still 50 percent faster than the double-speed Matsushita on the CDStone tests and up to 20 percent faster on the ani
mation tests.
So here's the bottom line: All the quad-speed drives I tested will play most commercially available multimedia equally well on a fast PC. That leaves you to consider price, features, and the future. If performance with future applications is your overwhelming concern, or if you're developing those applications, then either the Toshiba or Plextor units will serve you well. The NEC provides lots of extras for a moderate price, and isn't that far behind the two performance leaders. The AT interface gives TEAC an edge when it comes to simplicity, but when more demanding video hits store shelves, TEAC's slow performance could be a liability.
ABOUT THE PRODUCTS
NEC MultiSpin 4Xe Model CDR-601K external, with adapter $595
NEC Technologies, Inc.
1255 Michael Dr.
Wood Dale, IL 60191
(800) 632-4636
(708) 860-9500
fax: (800) 366-0476
Plextor 4Plex 43CH internal, with adapter $549
Plextor
4255
Burton Dr.
Santa Clara, CA 95054
(800) 475-3986
(408) 980-1838
fax: (408) 986-1010
TEAC SuperQuad Model CD-55A internal, with adapter $599
TEAC America, Inc.
7733 Telegraph Rd.
Montebello, CA 90640
(213) 726-0303
fax: (213) 727-7672
Toshiba XM-3501B internal, with adapter $645
Toshiba America Information Systems, Inc.
Disk Products Division.
9740 Irvine Blvd.
Irvine, CA 92713
(714) 457-0777
illustration_link (119 Kbytes)
All tests were run on a Dell Dimension 66V (66-MHz 486DX2) with a 64-bit Number Nine VL-Bus graphics accelerator. The Dell's double-speed Matsushita CD-ROM drive served as a basis for comparison. The CDStone tests measure access times (full stroke, one-third stroke, and random access) and data read rates (long block
and short block), as well as CPU use. The CDStone index uses a typical single-speed drive as its baseline.
illustration_link (87 Kbytes)
The AutoCAD animation tests simply measure the time it takes each of three AutoCAD animations to complete. The video tests shown here measure the frame rate playback and completion time of two versions of the same Video for Windows file. One uses Cinepak compression and is recorded at a data rate of 600 KBps. The second uses Indeo compression and is recorded at 475 KBps. Note that all the drives, even the Dell's original double-speed Matsushita, ran 150-KBps and 300-KBps files at their full rate.
photo_link (37 Kbytes)
A stack of four quad-speed CD-ROM drives (from top to bottom): TEAC America's SuperQuad, Toshiba's XM-3501B, Plextor's 4Plex, and NEC Technologies' MultiSpin 4Xe. List prices with host adapter range between $549 and $645. The TEAC drive uses a proprietary AT interface compatible with some Sound Blaster cards; the other three are SCSI drives. The NEC is an external unit (internal also available); the others are internal. The Plextor and Toshiba drives provided the best performance.
miken@bix.com
.
Quad-Speed CD-ROM Delivers
