3.2 RAM (Random Access Memory)

Question 1

RAM

Answer 1

• temporary storage area when a user loads an application or document
• holds data that the CPU needs in order to complete tasks
• volatile (data is lost when computer is shut down)
• black rectangular chip on memory module

Question 2

DIMM

Answer 2

Dual Inline Memory Module
- 64 bit data width
- contains black rectangular components called RAM

Question 3

SO-DIMM

Answer 3

Small Outline Dual Inline Memory Module
- half the width of DIMM
- used in laptops and other portable devices

Question 4

DRAM

Answer 4

Dynamic Random Access Memory
- one of the basic types of RAM
- dynamic: needs constant refreshing to preserve data
- random access: any storage location can be accessed directly
(unlike older storage where data is accessed in a fixed sequence)

Question 5

SRAM

Answer 5

Static RAM
- faster and more expensive than DRAM
- requires constant power (volatile) but no refreshing
- lower capacity than DRAM
- utilized for CPU cache memory chips

Question 6

SDRAM

Answer 6

Synchronous DRAM
- a clock on the system regulates the flow of data in and out of the module
- queue up one process while waiting for another

Question 7

SDR vs DDR

Answer 7

Single Data Rate: transfer data once in a clock cycle
Double Data Rate: transfer data twice in a clock cycle

Different DDR memory modules have notches in different places to prevent wrong insertion

Question 8

DDR3 SDRAM

Answer 8

• twice the rate of DDR2
• max 16 GB per DIMM
• 240 contact pin

Question 9

DDR4 SDRAM

Answer 9

• speed increases
• max 64 GB per DIMM
• 288 contact pins

Question 10

DDR5 SDRAM

Answer 10

• faster data transfer between the RAM and motherboard
• max 64 GB per DIMM
• 288 contact pins

Question 11

Virtual RAM

Answer 11

• aka swap file, page file, swap partition
• temporarily move currently unused app data to storage (hard drive or SSD)
• frees up memory for other programs/apps
• managed automatically by the OS

Question 12

Multi-Channel Memory

Answer 12

• # of channels refer to # of memory modules
• takes throughput and spreads it through multiple memory modules
• check motherboard manual to find correct memory module installation

Question 13

Parity Memory

Answer 13

• adds an additional parity bit for error detection
• won’t always detect an error
• can’t correct errors
• extra RAM chip on memory module

Question 14

Error Correction Code (ECC)

Answer 14

• detects errors and corrects on the fly
• not all systems use ECC
• slower and more expensive compared to non-ECC

Question 15

For optimal performance on a multi-channel memory architecture, the memory modules should:

Answer 15

• be matching types
• have matching speeds and capacity
• be installed in the appropriate memory slot