Dell OptiPlex GX240 User Manual

Page 291

PXE

Pre-boot eXecution Environment. A standard of

WfM

that allows networked

computers that do not have an

to be configured and started remotely.

PXE benefits include:

•

The client computer does not necessarily need its own OS or even a hard drive.

•

The client computer can be remotely shut down and restarted.

•

Since PXE is an industry standard, new computers can easily be added to the
network.

RAID

Redundant Array of Independent Disks. A system of two or more drives working
together for performance and fault tolerance. RAID drives are typically used
on servers and high-end

PCs

There are a number of different RAID levels. The three most common are 0,
3, and 5:

•

Level 0: Provides

data striping

but no redundancy. This improves performance

but does not provide fault tolerance.

•

Level 3: Same as Level 0, but also reserves one dedicated drive for error
correction data, providing good performance and some level of fault tolerance.

•

Level 5: Provides data striping at the

byte

level and also stripe error correction

information. This results in excellent performance and good fault tolerance.

RAM

Random-access memory. The primary temporary storage area for program
instructions and data. RAM is stored in

chips

on small circuit boards called

SIMMs

DIMMs

, or

RIMMs

, that attach to the system board. RAM, unlike

ROM

, is volatile, which means that, when you turn off your computer, any

information stored in RAM is lost.

Rambus

Rambus is a memory technology that is designed to work with existing system
board standards as an alternative to

DRAM

. See also

RIMM

RDRAM

, and

DRDRAM

RDRAM

Rambus

dynamic random-access memory (

DRAM

). A memory subsystem that

can optimally transfer up to 1.6 billion

bytes

of data per second. The

subsystem consists of

RAM

, the RAM controller, and the

bus

connecting

RAM to the

microprocessor

and other devices in the computer. See also

DRDRAM