Computer Maintenance

RAID Level: 4 Min # of Drives: 3

Block-level data striping with dedicated parity

RAID Level: 3 Min # of Drives: 3

Byte-level data striping with dedicated parity

ECC

Error Correction Code memory can detect multiple bit errors in memory and correct single bit errors in memory.

RAID Level: 2 Min # of Drives: 2

Error-Correcting Coding

RAID Level: 6 Min # of Drives: 4

Independent Data Disks with Double Parity

ISA

Industry Standard Architecture is an 8-bit or 16-bit expansion slot. This is older technology and is seldom used.

MCA

Microchannel Architecture is an IBM-proprietary 32-bit expansion slot. This is older technology and is seldom used.

PROM

Programmable read-only memory. Information is written to a PROM chip after it is manufactured. A PROM chip cannot be erased or re-written.

RDRAM

RAMBus DRAM is a memory chip that was developed to communicate at very high rates of speed. RDRAM chips are not commonly used.

RIMM

RAMBus Inline Memory Module is a circuit board that holds RDRAM chips. A typical RIMM has a 184-pin configuration.

ROM

Read-only memory chips. Information is written to a ROM chip when it is manufactured. A ROM chip cannot be erased or re-written and is obsolete.

SIMM

Single Inline Memory Module is a small circuit board that holds several memory chips. SIMMs have 30-pin or 72-pin configurations.

SODIMM

Small Outline DIMM has a 72-pin and 100-pin configurations for support of 32-bit transfers or a 144-pin, 200-pin, and 204-pin configurations for support of 64-bit transfers. This smaller, more condensed version of DIMM provides random access data storage that is ideal for use in laptops, printers, and other devices where conserving space is desirable.

SRAM

Static RAM is a memory chip that is used as cache memory. SRAM is much faster than DRAM and does not have to be refreshed as often. SRAM is much more expensive than DRAM.

SDRAM

Synchronous DRAM is DRAM that operates in synchronization with the memory bus. The memory bus is the data path between the CPU and the main memory. Control signals are used to coordinate the exchange of data between SDRAM and the CPU.

AGP

AGP is designed to be used by video adapters. Advancements in the specification for AGP allow for bandwidth increase. The bandwidth of the port can be multiplied 2X, 4X, or 8X

RAID Level: 0+1 Min # of Drives: 4

Combination of data striping and mirroring

RAID Level: 5 Min # of Drives: 3

Combination of data striping and parity

RAID Level: 0 Min # of Drives: 2

Data striping without redundancy

RAID Level: 1 Min # of Drives: 2

Disk Mirroring

DDR2 SDRAM

Double Data Rate 2 SDRAM is a faster than DDR-SDRAM memory. DDR2 SDRAM improves performance over DDR SDRAM by decreasing noise and crosstalk between the signal wires.

DDR3 SDRAM

Double Data Rate 3 SDRAM expands memory bandwidth by doubling the clock rate of DDR2 SDRAM. DDR3 SDRAM consumes less power and generates less heat than DDR2 SDRAM.

DDR SDRAM

Double Data Rate SDRAM is memory that transfers data twice as fast as SDRAM. DDR SDRAM increases performance by transferring data twice per clock cycle.

DIMM MEMORY

Dual Inline Memory Module is a circuit board that holds SDRAM, DDR SDRAM, DDR2 SDRAM, and DDR3 SDRAM chips. There are 168-pin SDRAM DIMMs, 184-pin DDR DIMMs, and 240-pin DDR2 and DDR3 DIMMs.

DIP

Dual Inline Package is an individual memory chip. A DIP has dual rows of pins used to attach it to the motherboard.

DRAM

Dynamic RAM is a memory chip that is used as main memory. DRAM must be constantly refreshed with pulses of electricity in order to maintain the data stored within the chip.

EEPROM

Electrically erasable programmable read-only memory. Information is written to an EEPROM chip after it is manufactured. EEPROM chips are also called Flash ROMs. An EEPROM chip can be erased and re-written without having to remove the chip from the computer.

EPROM

Erasable programmable read-only memory. Information is written to an EPROM chip after it is manufactured. An EPROM chip can be erased with exposure to UV light. Special equipment is required.

EDO MEMORY

Extended Data Out RAM is memory that overlaps consecutive data accesses. This speeds up the access time to retrieve data from memory, because the CPU does not have to wait for one data access cycle to end before another data access cycle begins.

EISA

Extended Industry Standard Architecture is a 32-bit expansion slot. This is older technology and is seldom used

FPM MEMORY

Fast Page Mode DRAM is memory that supports paging. Paging enables faster access to the data than regular DRAM. FPM memory was used in Intel 486 and Pentium systems.

L1

L1 cache is internal cache and is integrated into the CPU.

L2

L2 cache is external cache and was originally mounted on the motherboard near the CPU. L2 cache is now integrated into the CPU.

L3

L3 cache is used on some high-end workstations and server CPUs.

Mini PCI

Mini PCI is a 32-bit bus used by laptops. Mini PCI has 3 different form factors; Type I, Type II, and Type III

RAID Level: 10 Min # of Drives: 4 (Must be even)

Mirrored set in a striped set

NonParity

Nonparity memory does not check for errors in memory.

PCIe

PCI Express is a serial bus expansion slot. PCIe has x1, x4, x8 and x16 slots. PCIe is replacing AGP as an expansion slot for video adapters and can be used for other types of adapters.

PCI-X

PCI-Extended is a 32-bit bus with higher bandwidth than the PCI Bus. PCI-X can run up to four times faster than PCI

Parity

Parity memory contains eight bits for data and one bit for error checking. The error-checking bit is called a parity bit.

PCI

Peripheral Component Interconnect is a 32-bit or 64-bit expansion slot. PCI is the standards slot currently used in most computers