Memory Architecture

Question 1

What is memory latency?

Answer 1

The time it takes to retrieve binary data from memory

Question 2

DRAM vs SRAM

Answer 2

DRAM is slower, smaller, cheaper and needs refreshing whereas SRAM is faster, larger, expensive and doesn’t need refreshing

Question 3

Cache vs RAM

Answer 3

Cache is faster, located closer to the CPU, expensive but is smaller compared to RAM

Question 4

Does cache use SRAM or DRAM?

Answer 4

SRAM

Question 5

List the levels of the memory hierarchy (fastest to slowest).

Answer 5

Cache (L1, L2, L3)
RAM
Secondary Memory

Question 6

List the levels of Cache

Answer 6

L1 - Fastest, slower, and embedded within the CPU
L2 - Larger and can be embedded within the CPU
L3 - Supports L1 and L2, slower but larger

(As levels go down it gets slower but larger)

Question 7

What is stored in RAM?

Answer 7

Programs, data, and addresses currently in use

Question 8

What is Virtual memory and why is it used?

Answer 8

Logical memory that appears to exist in the RAM but is stored in SSD and HDD and it is used to run larger programs that cannot fit in the physical RAM

Question 9

Cache Hit Vs Miss

Answer 9

A cache hit is when required data is found within the cache memory whereas cache miss is when data cannot be found and has to be found within physical memory

Question 10

What is the formula to calculate number of locations within bus?

Answer 10

2^width of bus