Chapter 4: RAM

Question 1

Random-access memory (RAM)

Answer 1

Main memory that the CPU uses to store or retrieve data, which can be done in any order, regardless of whatever the CPU last accessed

Question 2

Static RAM (SRAM)

Answer 2

RAM that does not need to be periodically refreshed, soldered directly to a printed circuity board (PCB) or integrated directly to a chip, Faster and found in smaller quantities than DRAM

Question 3

Dynamic RAM (DRAM)

Answer 3

RAM that does need to be periodically refreshed, Every bit of information stored in a separate capacitor which loses charge over time, causing data to fade unless the capacitor is recharged or refreshed, Slower but can reach high capacities

Question 4

Read-Only Memory (ROM)

Answer 4

Non-volatile, Historically could only be read from not written to, but now can do both

Question 5

Synchronous DRAM (SDRAM)

Answer 5

DRAM that is synchronized to the base clock of the mobo

Question 6

Double Data Rate (DDR)

Answer 6

Synchronized to the memory clock like SDRAM, 64-bit wide bus allowing for 8 bytes of data per cycle

Question 7

Bandwidth or Data Transfer Rate for all types of DDR (Formula)

Answer 7

Multiply the megatransfers per second (MT/s) by 8

E.g. 200 MT/s x 8 = 1,600 MB/s

Question 8

Number of pins in DDR1

Answer 8

184

Question 9

Number of pins in DDR2

Answer 9

240

Question 10

Number of pins in DDR3

Answer 10

240

Question 11

MT/s in DDR3-1333

Answer 11

1333 MT/s

Question 12

I/O clock speed for DDR3-1333

Answer 12

667 MHz (Half the megatransfers)

Question 13

Data transfer rate of PC3-10600

Answer 13

10,600 MB/s

Question 14

Number of pins in DDR4

Answer 14

288

Question 15

Memory latency or Column Address Strobe (CAS or CL) latency

Answer 15

The slight delay the occurs while the memory module responds to the memory controller; Higher the CL number, the longer the delay

Question 16

Single-sided memory module

Answer 16

Refers to a memory module with a single “bank” of chips that the computer’s memory controller can access all at once

Question 17

Double-sided memory module

Answer 17

Refers to a memory module with its chips divided into two “sides” known as banks; Only one “side” can be seen by the computer at any time and to use the second half, the computer must switch

Question 18

RAM Parity

Answer 18

When memory stores an extra bit (known as a parity bit) used for error detection

Question 19

Error Correction Code (ECC)

Answer 19

Can detect and correct errors in RAM; May be used by real time applications; Slowest and most expensive of RAM types