Cache Memory Quiz

What is the primary purpose of cache memory?

• To permanently store data

• To act as a high-speed buffer between CPU and main memory

• To replace the hard disk

• To manage virtual memory

Which principle states that recently accessed data is likely to be accessed again soon?

• Spatial Locality

• Random Locality

• Temporal Locality

• Sequential Locality

In a direct-mapped cache, each main memory block maps to:

• Any cache line

• Exactly one specific cache line

• A set of N cache lines

• The first available cache line

Which cache write policy writes data to BOTH cache and main memory simultaneously?

• Write-Back

• Write-Once

• Write-Through

• Write-Allocate

What does a 'dirty bit' indicate in a cache line?

• The data is corrupted

• The data has been modified but not yet written to main memory

• The cache line is empty

• The data is read-only

What is the main disadvantage of the direct-mapped cache?

• High hardware cost

• Very slow access time

• High conflict miss rate (thrashing)

• Cannot store large data

The cache replacement policy that evicts the line unused for the longest time is:

• FIFO

• LRU (Least Recently Used)

• Random Replacement

• MRU (Most Recently Used)

What is the formula for Effective Memory Access Time (AMAT)?

• AMAT = Hit Time × Hit Rate

• AMAT = Hit Time + Miss Rate × Miss Penalty

• AMAT = Miss Penalty / Hit Rate

• AMAT = Hit Rate + Miss Rate × Hit Time

Which allocation policy fetches a block into cache on a WRITE miss?

• No-Write-Allocate

• Write-Around

• Write-Allocate (Fetch on Write)

• Write-Through

What is the primary purpose of a Write Buffer in Write-Through caches?

• To improve Write-Back performance

• To queue write operations and prevent CPU stalls

• To allocate memory blocks

• To store frequently accessed data