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SATA
Serial ATA. Latest version of ATA that uses 7 wires interface.(instead
of the traditional 40 wires parallel IDE/ATA interfaces).
SCSI
small computer system interface. Mainly used in Servers and
Macintoshes to connect high performance hard disks.
- SCSI-1 - An 8-bit (narrow) SCSI bus (25 pins connector) that transfer up to 4 MBps.
- SCSI-2 - A narrow SCSI (8-bit) that use 50 pins connector.
- Wide SCSI - A 16-bit SCSI.
- Fast SCSI - A faster narrow SCSI that transfer up to 10 MBps.
- Fast Wide SCSI - A 16-bit SCSI that transfer up to 20 MBps.
- Ultra SCSI - A narrow SCSI that transfer up to 20 MBps.
- Ultra Wide SCSI - A 16-bit SCSI that transfer up to 40 MBps.
- Ultra2 SCSI - A narrow SCSI that transfer up to 40 MBps.
- Wide Ultra2 SCSI: A 16-bit SCSI that transfer up to 80 MBps.
SCA
Single Connector Attachment. The SCA interface was designed
for using hot swappable hard disks. SCA interface hard drives
connect to a SCSI backplane that provides power, configuration
settings, and SCSI termination to the drives.
SD card
Secure Digital Memory card. A type of flash memory card for data storage devices commonly used in portable devices measuring 32mm x 24mm x 2.1mm. New ultra-small generations include miniSD card (21.5mm x 20mm x 1.4mm) and microSD Card (15mm x 11mm x 1mm) which have the same features.
Sector
A smaller unit found in each track of a cylinder disk with magnetic
marking and an ID number. Sectors have a sector header and an
error correction code (ECC).
Seek
Time
The seek time of a hard disk is the amount of time
needed by the read/write heads to move from one track to another
destinated track.
Switching between tracks requires the actuator to move the r/w head arms physically. The amount of time needed to travel between two tracks depends on the distance.
- Average Seek Time - an average seek time from one random track or cylinder to any other track. (Typically 8 to 12 ms)
- Track-to-Track Seek Time - the time needed to seek between adjacent tracks. (Typically 3 ms or less)
- Full
Stroke Seek Time - the time needed to seek from the innermost
track to the outermost track. (Typically 20 ms)
Spindle
the axle on which a disk turns.
Striping
storing of data by distributing them into multiple disks in
a certain pattern, so as to achieve certain advantages such as
speed, volume space or redundancy depending on the striping method.
