Low-Cost High-Performance Removable Storage
Removable storage technologies
Data stored on a removable hard disk can be read about as quickly as data stored on a fixed hard disk
of comparable size. You really won't notice the difference, if you connect the drive to your computer
using a suitably fast interface (SCSI or EIDE, if possible). Because you can also carry a removable
hard-disk cartridge around with you wherever you need it, it's the ideal storage medium for your
personal data and backups in most situations. A removable hard-disk drive with a cartridge typically
costs $30 to $200, depending on capacity and speed. Even at the low end of this price range, you can
have disk access that's twice as fast as a Zip drive, and larger capacity, so there's little reason
for any personal computer not to be equipped with one of these devices.
Sometimes, however, other considerations will outweigh the performance benefits of a hard disk. To be
sure you're buying the right type of drive for your needs, first consider some of the alternatives
listed in the table below.
| Technology |
Typical avg. seek time |
Outstanding benefit |
| Removable hard disk |
10 - 14 ms |
speed |
| Zip disk |
29 ms |
popularity |
| high-capacity floppy diskette |
slow |
compatibility with floppy diskettes |
| CD-RW |
slow |
compatibility with CD-ROM disks |