Today's double-speed drives demonstrate sameness rather than distinction. The 23 double-speed drives we tested represent only eight different drive mechanisms. Toshiba's mechanism is the dominant one in this sample: 11 of the drives used either Toshiba's T3401 or T4101 model. Accordingly, performance varied only slightly across the entire sample (by approximately 10 percent), and the scores for the drives using the Toshiba mechanisms were almost identical. The T3401-based models produced sequential throughput of about 331 KBps, while the T4101-based models posted throughput of about 301 KBps.
Nevertheless, the exceptions to the Toshiba-mechanism rule often performed well. Our Best Overall drive, Plextor's DM-5028, uses a Plextor mechanism, and its throughput score was th
e fastest of the drives we ranked in that category.
The standard buffer size for double-speed drives is 256 KB, although we did see a handful with 128 KB or even 64 KB (including the Plextor). The buffer is especially important during times when the drive is waiting for the system to display an image on the screen: In such cases, the drive can read ahead and fill the buffer with data. However, the relatively small size of CD-ROM drive buffers (even when they're the larger 256-KB buffers) don't necessarily bring faster performance.
Firmware plays a prime role in how efficiently the drive uses its buffer. The system CPU stops every time it issues a read-ahead command to the CD-ROM drive. Too many such commands translates into noticeably slow system performance. CD-ROM vendors use two approaches for buffering. In circular buffer read-ahead, the drive continuously reads with just one interrupt from the main processor. This keeps the buffer full and improves throughput. Another approach is to copy th
e drive's table of contents or root-directory information into the buffer memory, which can reduce random-access time.
The interface adapter and the device driver also play an important role in drive performance, especially in CPU utilization. Several drive vendors, including Philips LMS, Reveal, Hitachi, and Plextor offer a standard bundle of an 8-bit SCSI adapter. Such adapters are handy if your system lacks SCSI and you are not planning to run multimedia applications. If you are buying a CD-ROM drive for video-intensive applications, consider a higher-performing 16-bit ISA or even an EISA SCSI adapter.
Some drives, such as Hitachi's CDR-1900SPC, come with a proprietary SCSI adapter, which provides a performance edge over drives that use a standard SCSI adapter. However, proprietary adapters can't support SCSI peripherals, such as a hard drive.
Test results for CPU utilization can be especially important for finding drives that won't drop video frames when playing video off a CD. All th
e SCSI-based drives achieve performance within the standard MPC Level 2 specification, which is 40 percent for 150-KBps transfers and 60 percent for 300-KBps rates. None of the SCSI drives we tested dropped frames when they ran our test video file at a resolution of 320 by 240 pixels. By contrast, none of the three parallel-port drives we tested met the MPC Level 2 specification for CPU utilization, and each dropped 80 percent or more of the frames (see ``CD-ROM for the Road'' on page 182).
This generation of double-speed drives is also similar in their ease of use. Installation was never more difficult than connecting the proper cables to the SCSI port and loading a device driver. Front-panel controls were also easy to use for all these drives. Each product came with an eject button, an emergency manual-eject hole, an audio jack, and volume control on the front panel. Nevertheless, we did have a few favorite interface implementations that offered more than the standard items. If the drive had indicato
r lights or an LCD, it helped us tell when the CD was loaded in the drive. But some drives, such as CD's T3401, Legacy's CD-ROM 2x, MacProducts USA's Magic CD Pro, Mirror's CD ROM, PLI's CD ROM MS, and Reveal's The Entertainer, had no indicator light to tell you if a CD was loaded or if the power was on. In these cases, we had to press the eject button on the drive to see if the CD was inserted.
A note about NEC's triple-speed drive: The first NEC 3X MultiSpin drive we tested produced throughput scores that were inconsistent with triple-speed performance. A second drive couldn't complete our tests. Neither we nor NEC technicians could resolve the problem during our test cycle.
Rankings for Best and Lost Cost Considered
PERFORMANCE 70%
FEATURES 20%
EASE OF USE 10%
Rankings for Text Considered
PERFORMANCE 80%
FEATURES 20%
For the best in price and performance.
..
BEST OVERALL
Plextor DM-5028 DoubleSpeed Plus
This double-speed drive offers an excellent combination of price and performance. The $409 base drive ($469 with adapter) completed our sequential-throughput tests second fastest of all the double-speed drives we tested. Its CPU utilization was among the lowest and most efficient we tested, making this drive a good choice whether you need to search databases or run video. The DM-5028 achieves this performance with a small 64-KB buffer. Its text-search times were the fastest, although its random-access score was the lowest among the Best Overall drives.
SEQUENTIAL RANDOM
THROUGHPUT ACCESS
PRICE# (KBPS) (SECONDS)
Best Plextor DM-5028 DoubleSpeed Plus $409 336.2 0.34
Runner-up Toshiba America TXM-3401E $545 331.1 0.29
Runne
r-up Legacy CD-ROM 2x $575 331.3 0.26
Runner-up Mirror CD ROM Drive $259 331.2 0.26
Runner-up DEC RRD44-DA $549 331.9 0.27
Runner-up Peripheral PLI CD-ROM MS $743 331.5 0.27
Runner-up MacProducts USA Magic CD Pro $459 331.4 0.26
Runner-up FWB hammerCD $749 331.4 0.26
CPU UTILIZATIONI(%)
150 KBPS 300 KBPS
Best Plextor DM-5028 DoubleSpeed Plus 14.22 29.40
Runner-up Toshiba America TXM-3401E 15.34 29.02
Runner-up Legacy CD-ROM 2x 15.27 30.19
Runner-up Mirror CD ROM Drive 15.22 29.45
Runner-up DEC RRD44-DA 18.40 35.58
Runner-up Peripheral PLI CD-ROM MS 15.91 31.82
Runner-
up MacProducts USA Magic CD Pro 19.12 36.92
Runner-up FWB hammerCD 15.22 29.04
FEATURES EASE OF
SCORE USE
Best Plextor DM-5028 DoubleSpeed Plus *** ***
Runner-up Toshiba America TXM-3401E *** ****
Runner-up Legacy CD-ROM 2x **** ***
Runner-up Mirror CD ROM Drive *** ***
Runner-up DEC RRD44-DA **** ***
Runner-up Peripheral PLI CD-ROM MS *** ***
Runner-up MacProducts USA Magic CD Pro *** ***
Runner-up FWB hammerCD ** ****
BUFFER
SIZE DRIVE WARRANTY
(KB) VENDOR
(YEARS)
Best Plextor DM-5028 DoubleSpeed Plus 64 Plextor 1
Runner-up Toshiba America TXM-3401E 256 Toshiba 1
Runner-up Legacy CD-ROM 2x 256 Toshiba 1
Runner-up Mirror CD ROM Drive 256 Toshiba 1
Runner-up DEC RRD44-DA 256 Toshiba 3
Runner-up Peripheral PLI CD-ROM MS 256 Toshiba 1
Runner-up MacProducts USA Magic CD Pro 256 Toshiba 1
Runner-up FWB hammerCD 256 Toshiba 2
KEY
Excellent ****
Good ***
Fair **
Poor *
# Doesn't include adapter price; see ``Roll Call.''
Need low cost and fast speed?
LOW COST
Mirror CD ROM Drive
At $259, this drive known primarily in the Mac market easily met the under-$500 requirement for this category. It makes only minor compromises in speed compared to the Best Overall winner. If you're a PC user, you'll need to sp
end approximately $93 more for an ISA-based SCSI adapter and cable. For this still-economical price, you'll see solid performance from this Toshiba-mechanism drive: Its speed scores rank near the top of the more expensive Best Overall leaders.
SEQUENTIAL RANDOM
THROUGHPUT ACCESS
PRICE# (KBPS) (SECONDS)
Best Mirror CD ROM Drive $259 331.2 0.26
Runner-up MacProducts USA Magic CD Pro $459 331.4 0.26
Runner-up CD Technology CD Porta-Drive T3401 $500 331.3 0.26
Runner-up Plextor DM-5028 DoubleSpeed Plus $409 336.2 0.34
CPU UTILIZATIONI(%)
150 KBPS 300 KBPS
Best Mirror CD ROM Drive 15.22 29.45
Runner-up MacProducts USA Magic C
D Pro 19.12 36.92
Runner-up CD Technology CD Porta-Drive T3401 15.76 30.55
Runner-up Plextor DM-5028 DoubleSpeed Plus 14.22 29.40
FEATURES EASE OF
SCORE USE
Best Mirror CD ROM Drive *** ***
Runner-up MacProducts USA Magic CD Pro *** ***
Runner-up CD Technology CD Porta-Drive T3401 *** **
Runner-up Plextor DM-5028 DoubleSpeed Plus *** ***
BUFFER
SIZE DRIVE WARRANTY
(KB) VENDOR (YEARS)
Best Mirror CD ROM Drive 256 Toshiba 1
Runner-up MacProducts USA Magic CD Pro 256 Toshiba 1
Runner-up CD Technology CD Porta-Drive T3401 256 Toshiba
1
Runner-up Plextor DM-5028 DoubleSpeed Plus 64 Plextor 1
KEY
Excellent ****
Good ***
Fair **
Poor *
# Doesn't include adapter price; see ``Roll Call.''
Need to find data quickly?
TEXT
CD Technology CD Porta-Drive T3401
This svelte, 3-pound drive achieved the highest overall performance score in our combined text, sequential throughput, and random-access tests. A Toshiba-mechanism drive, the T3401 can run off of its external power supply. Note that the drive uses a proprietary SCSI connection, which can help performance but doesn't support other SCSI peripherals.
SEQUENTIAL RANDOM
THROUGHPUT ACCESS
PRICE# (KBPS) (SECONDS)
Best CD Technology Porta-Drive T3401 $500 331.3 0.26
Runner-up Legacy CD-ROM 2x $575 3
31.3 0.26
Runner-up MacProducts USA Magic CD Pro $459 331.4 0.26
Runner-up DEC RRD44-DA $549 331.9 0.27
Runner-up Toshiba America TXM-3401E $545 331.1 0.29
Runner-up Plextor DoubleSpeed Plus $409 336.2 0.34
TEXT SEARCH (SECONDS)
ONE-WORD BOOLEAN
Best CD Technology Porta-Drive T3401 15.23 15.08
Runner-up Legacy CD-ROM 2x 15.2 15.42
Runner-up MacProducts USA Magic CD Pro 15.35 15.37
Runner-up DEC RRD44-DA 16.24 15.29
Runner-up Toshiba America TXM-3401E 15.31 15.23
Runner-up Plextor DoubleSpeed Plus 15.09 15.06
CPU UTILIZATIONI(%)
150 KBPS 300 KBPS
Best CD Technology Porta-Drive T340
1 15.76 30.55
Runner-up Legacy CD-ROM 2x 15.27 30.19
Runner-up MacProducts USA Magic CD Pro 19.12 36.92
Runner-up DEC RRD44-DA 18.40 35.58
Runner-up Toshiba America TXM-3401E 15.34 29.02
Runner-up Plextor DoubleSpeed Plus 14.22 29.40
FEATURES EASE OF
SCORE USE
Best CD Technology Porta-Drive T3401 *** **
Runner-up Legacy CD-ROM 2x **** ***
Runner-up MacProducts USA Magic CD Pro *** ***
Runner-up DEC RRD44-DA **** ***
Runner-up Toshiba America TXM-3401E *** ****
Runner-up Plextor DoubleSpeed Plus *** ***
BUFFER
SIZE DRIVE
(KB) VENDOR
Best CD Technology Porta-Drive T3401 256 Toshiba
Runner-up Legacy CD-ROM 2x 256 Toshiba
Runner-up MacProducts USA Magic CD Pro 256 Toshiba
Runner-up DEC RRD44-DA 256 Toshiba
Runner-up Toshiba America TXM-3401E 256 Toshiba
Runner-up Plextor DoubleSpeed Plus 64 Plextor
KEY
Excellent ****
Good ***
Fair **
Poor *
# Doesn't include adapter price; see ``Roll Call.''
The Best Double-Speed CD-ROM Drives
