| IDE |
Also known
as ATA (Advanced Technology Attachment) by ANSI. IDE technology was developed
to overcome CMOS limitations in older computers. IDE is used as one of the
standard interfaces between a computer's input/output devices and the motherboard.
Although it can be used with other bus standards the IDE interface was originally
based on the IBM PC ISA 16 bit bus standard. The nature of the IDE interface
allows for only two components to be attached to each bus; one designated
master and the other slave. The IDE bus is unterminated. Therefore, an IDE
cable cannot exceed 18 inches. |
| Idle |
An ordered set transmitted
continuously over a link when no data is being transmitted to maintain
an active link. It helps maintain bit, byte, and word synchronization.
|
| IEEE |
Institute
of Electrical and Electronics Engineers: a membership organization that
includes engineers, scientists and students in electronics and allied fields.
Best known for its involvement in setting standards for computers and communications,
such as the widely followed IEEE 802 standards for Local Area Networks. |
| Initiator |
A
server or workstation on a Fibre Channel network that initiates transactions
to tapes or disks. |
| Intercabinet |
A specification
for copper cabling that allows up to 33-meter distances between cabinets. |
| Interface
|
A hardware
or software protocol, (contained in the electronics of the disk controller
and disk drive) that manages the exchange of data between the drive and
computer. The most common interfaces for small computer systems are AT (also
known as IDE) and SCSI. |
| Interface
Access Time (IAT) |
The necessary
time to issue an I/O command to the disk and to transfer the data over the
system bus. |
| Interface
Transfer Rate (IRT) |
The number
of commands and data transfers per second between the system bus and the
storage device. |
| IOPS |
I/O operations
per second. |
| IP |
Internet
Protocol. |
| IPI |
Intelligent
Peripheral Interface. |
| ISL |
Inter-switch
Link. |
| Isochronous |
Refers
to processes where data must be delivered within certain time constraints.
For example, multimedia streams require an isochronous transport mechanism
to ensure that data is delivered as fast as it is displayed and to ensure
that the audio is synchronized with the video. Contrast with Asynchronous
and Synchronous. |
| LAN |
Local Area
Network. |
| Latency |
The time
between initiating a request for data and the beginning of the actual data
transfer. For example, the average latency of a hard disk drive is easily
calculated from the spindle speed, as the time for half a rotation. |
| LBA |
Logical
Block Addressing: the scheme by which the BIOS passes an operating system
request for a given sector to a modern disk drive. |
| LED |
Light Emitting
Diode. |
| Level
1 Cache |
Cache that
is closest to the processor: typically located inside the CPU chip. Can
be implemented either as a unified cache or as separate sections for instructions
and data. Also referred to as primary cache or internal cache. |
| Level
2 Cache |
Cache that
is second closest to the processor; typically located on the system board.
Also referred to as secondary cache and external cache. |
| Level
3 Cache |
Level 3
Cache: a memory reservoir near the processor that boosts performance beyond
that possible with traditional two-level cache designs. First seen in early
1999 on AMD's K6-III CPU, a similar system was later used by Intel's 64-bit
Itanium processor. |
| Link
control |
A termination
handling physical and logical control of the Fibre Channel link for each
mode. |
| Link |
A bi-directional
point-to-point serial data channel. |
| Low-level
Format |
The result
of creating sectors on the disk surface so that the operating system can
access the required areas for generating the file structure. |
| Low
Profile |
Describes
drives built to the 3 1/2-inch form factor, which are only 1 inch high.
The standard form factor drives are 1.625 inches high. |
| LUNETA™ MFI |
Logical UNifier of Extensive Transfer Arrays Memory Flash Interface |
| LVD |
Low Voltage
Differential: the latest type of SCSI used by hard disk drives in entry-level
servers and workstations. Connects via a colored ribbon cable and a 68-pin
socket. Also known as Ultra Wide 2. |
