To meet the demands of the new business models and new applications,
storage technology is developing on several fronts and for different
classes of products. All product classes -- including optical,
tape, and disk -- are benefiting from these advances.
Optical Disk Drives
In the storage hierarchy, optical and magneto-optical products
fall into the bottom tier below solid state disk (SSD), disk drive,
and tape technology. Optical devices are primarily used for content
exchange, backup, and archival purposes and not for primary storage.
Products in this category include CD-Recordable (CD-R), CD-Rewritable
(CD-RW), DVD, WORM, MO disk, and the relatively new near-field
recording (NFR) technology (a high-capacity technology that offers
rewritable, random-access storage). CD-RW is the hottest removable
storage product, with shipments expected to continue to increase
significantly throughout 2000. The large installed base of CD
readers makes CD-RW ideal for file exchange as well as a reliable
form of backup.
Falling prices and new technologies are expected to push the market
for DVD drives. In the long term, the combination of low cost
per megabyte and rugged media will forge a considerable market
share, even taking archival and backup share from the tape market.
Tape Drives
Although the death of tape has been predicted for many years,
tape drives continue to dominate the market for backup and archival
applications. More new tape technologies have been introduced
in the past two years than ever before. Tape drives in the midrange
and enterprise class continue to show growth as new products--such
as virtual tape systems--make tape an even more cost-effective
storage medium, and developments--such as intelligent tape cartridges
that include built-in flash memory chips--provide a much higher
performance for finding a record or a file.
Competition is heating up in the high-end tape arena with three
relatively new formats--Quantum's Super DLTtape, Exabyte Corporation's
Mammoth-2 (M2), and the Linear Tape Open (LTO) technology--set
for widespread availability this year.
Quantum's Super DLTtape is an extension of digital-linear tape
(DLT) technology, which uses a linear serpentine method (or a
modified linear serpentine method called Symmetrical Phase Recording--SPR)
to write data to half-inch tape. The SuperDLTtape has a 100GB
capacity and a native transfer rate of 10MBps.
Exabyte's M2 tape drive is an 8mm helical scan drive that uses
a scanner design that is larger than other helical scan technologies,
such as digital data storage (DDS). The larger scanner accommodates
four read/write heads and embeds electronics directly on the scanner
heads. M2 has a transfer rate of 12MBps and a 60GB capacity.
Perhaps the most widely anticipated of these formats is LTO technology,
a joint venture by HP, IBM, and Seagate. LTO, an open standard,
is a bidirectional, multichannel extension of the digital linear
technology. Two formats are based on the LTO technology. The Ultrium
tape format is optimized for high capacity (it has a native capacity
of 100GB, with an data transfer rate of 20 MBps). The Accelis
format uses a shorter tape to optimize seek time and provide fast
access to data.
Travan and DDS are the most popular tape formats on the desktop
and for entry-level server configurations where backup is more
important than ever. The Travan format evolved from the industry-standard
quarter-inch cartridge (QIC); however the Travan format, with
capacities from 400MB to 20GB, offers higher capacity than earlier
QIC formats. The DDS format offers capacities of 4GB to 24GB of
compressed data.
IBM and StorageTek dominate the high-end tape drive market; Quantum,
the midrange; and Exabyte, HP, and Sony, the low end.
Disk Drives
Disk drive development is moving in two directions: one direction
emphasizes high capacity, while the other aims at better performance.
Magnetic disk drives will show a compounded 60 percent annual
growth rate in density (and 35 percent decrease in the price per
megabyte). At this rate, 3.5-inch drives are expected to reach
140GB by 2001, surpassing the need for capacity on desktops, while
2.5-inch drives will exceed 50GB. Leading enterprise disk-drive
manufacturers are moving from 7200rpm drives to 10,000rpm drives
for the professional market.
The new generation of disk drives will be intelligent, with microprocessors
adding computing power inside the device, providing more independence
to the drive and reducing some of the bottlenecks in the I/O path.
Very small disk drives (e.g., IBM's 340MB 1-inch disk drive) may
revolutionize the portable, mobile, and handheld markets.
The major disk-drive manufacturers include Fujitsu, Hitachi, IBM,
Maxtor Corporation, Quantum Corporation, Seagate Technology Inc.,
and Western Digital. Several recent acquisitions by some of these
manufacturers are evidence of their interest in broadening their
market. In September 1999, Quantum announced its acquisition of
Meridian Data, a leading supplier of workgroup NAS appliances;
and Maxtor announced its acquisition of Creative Design Solutions
(CDS), a leading participant in the NAS market. In December, Seagate
acquired XIOtech Corporation, a leader in virtual storage and
SAN solutions.
Solid State Disks
At the high point of the data storage hierarchy is SSD technology.
While SSDs behave like magnetic disk drives and appear to the
host computer as disk drives, an SSD stores data on high-density
arrays of DRAM memory chips, not magnetic disk. Using DRAM instead
of disk eliminates the mechanical delays associated with spinning
a hard disk and positioning the read/write heads. Thus, an SSD
drive's access time measures in microseconds instead of the millisecond
access times seen in disk drives. Adding just one or two SSD drives
to a disk array system for hot files can significantly improve
overall performance compared to the performance of a disk system
of all rigid disks.
However, the SSD market has so far been hindered by its high costs.
By 2002, the average cost per megabyte of SSD storage should fall
into the $4 range from today's $16 range, popularizing its use.
Despite the cost, ISPs have become large consumers of SSD drives,
adding them to their systems for cache purposes. As the need for
high-speed connections becomes more prevalent, the use of solid
state memory in cache applications will become more commonplace.
Recent product announcements include a Fibre Channel-connected
SSD that can be directly shared in SAN configurations.
Flash Memory
New memory technologies have led to flash memory, an ideal medium
for lower capacities in applications where either nonvolatility
is important and/or small size is of essence, as in cellular phones,
handheld PDAs, and digital cameras. Flash memory is related to
electrically erasable, programmable read-only memory (EEPROM)
that can be erased by running a higher-than-normal voltage through
the chip. The advantage of flash memory over EEPROM is that it
doesn't need voltages higher than those normally found in computers.
However, except for military or severe-environment applications,
flash memory's relatively high cost per megabyte limits its use
to applications where a few megabytes of storage are sufficient..
The price per megabyte has come down in one year from $30 - $40
to $10 - $25 and is expected to reach $1 - $2 per megabyte by
2001.
Rapid developments in a variety of technologies and breakthroughs
in performance and capacity in all areas of computer hardware
and software allow deployment of new applications that, in turn,
drive market demand for even more innovation. Storage technologies
continue to evolve to meet the growing storage needs of organizations
and individuals.
By: Farid Neema
PERIPHERAL CONCEPTS, INC.
351 Hitchcock Way, Suite #B-200
Santa Barbara, California, 93105
Tel: (805) 563-9491
fneema@silcom.com
This article was published in the Marh issue of Windows2000 Magazine