The many standards of the QIC-based recording technology write data to tape using a complex multihead assembly. The drives record data by running tape past a stationary-head assembly at up to 120 inches per second serially on a straight track using the GCR (Group-Coded Recording) encoding method. GCR is used on many magnetic tapes as well as on Apple II and Mac 400- and 800-KB floppy disks. The tape then reverses direction and records data on a parallel track in a serpentine pattern.
The attraction of QIC drives centers on high capacity, low medium cost, and fast file access. However, QIC drawbacks are high drive costs, low data transfer rates, and incompatibility between different manufacturers' drives and data-recording formats. Originally, the only thing standard about QIC systems was the medium. Manufacturers varied the number of tracks per tape, t
he density of data, and even how the drives connected to computers. Each system was proprietary. In 1982 vendors formed the QIC Committee to form standards. Increasingly since then, QIC drives are gaining backward compatibility.
The QIC technology, developed and marketed by 3M, claims close to 10 million installations. Advances in materials technology and polymer chemistry have contributed to the medium's performance, capacity, and longevity. Improvements in medium formulation (i.e., high coercivity and cobalt-modified gamma ferric-oxide pigments), better tape substrate and binders, and improved mechanical design (i.e., a double-textured drive belt, corner-roller and hub, and better lubrication) gave rise to data cartridges with capacities in excess of 5 GB. QIC drives use hardware compression algorithms that enable them to transfer compressed data at a rate of 1.6 MBps (or 1 GB in 11 minutes). QIC, Inc., the QIC development standards association, also specifies a fast-search capability that matches th
at of the DDS-2 format and is twice as fast as the fast-search capability of 8-mm tape drives. The quoted MTBF (mean time between failures) of QIC-drive mechanisms is 200,000 hours. The length of QIC tapes can vary from 300 to 1200 feet, so the capacities vary as well. Data can be recorded on up to 44 tracks along the tape, usually in a serial, serpentine pattern. Although there are almost two dozen QIC recording formats, QIC, Inc. is working to ensure backward compatibility.
Advanced design features for QIC cartridges include a mirror mechanism and position sense holes for tape position sensing, a write-protect plug, and a tape cover door to protect the magnetic medium from contaminants when not in use. These all contribute to the longevity QIC drives have enjoyed in the PC market.
Yet the QIC-drive technology, despite new initiatives for higher-capacity standards (see ``Low-End QIC Gets a Capacity Boost''), is falling behind advances in hard drive capacities that seem to increase by the day. T
his is helping high-capacity tape-drive technologies such as DLT earn market share in the LAN market.
We tested only
two QIC drives
: the Tecmar Proline CX QIC 10 and the Legacy QIC 10. Both use Rexon's Wangtek 9500 drive mechanism. The Legacy QIC 10 provides better performance than the Tecmar drive and costs $650 less. However, both drives' test results were significantly slower than the over 400-MB-per-minute transfer rate that is claimed for the QIC 10 drive. But remember: We tested them in overwrite mode rather than letting them append to existing data. QIC 10 drives usually perform much better in sequential append configuration than in overwrite mode.
QIC Drive Winner
The Legacy QIC 10 is the better of the two QIC drives we tested because of its overall score and competitive price.
TABLE OF QIC FEATURES
Price Server Overall NT Overall
Legacy QIC 10 $1800 7.56
6.68
Rexon/Tecmar Proline CX QIC 10 $2449 7.27 6.23
Performance
Server NT
Legacy QIC 10 7.56 6.38
Rexon/Tecmar Proline CX QIC 10 7.14 5.75
Features Usability
Legacy QIC 10 ** ***
Rexon/Tecmar Proline CX QIC 10 *** **
(Both QIC drives use Rexon's Wangtek 9500 drive mechanism.)
Key:
Excellent ****
Good ***
Fair **
Poor *
photo_link (20 Kbytes)
The two QIC drives we tested (from the left): Legacy's Legacy QIC 10, and Rexon's Tecmar Proline CX QIC 10. A 6- by 4-inch cartridge is pictured; smaller minicartridges are popular.
QIC Drives
