Important Cache Memory MCQ Questions with Answers (Set 2) | IBPS IT Officer, GATE

This set of Cache Memory MCQ Question covers advanced concepts of Computer Organization and Architecture (COA) related to cache mapping techniques, tag and index calculation, multi-level cache systems, set-associative mapping, cache write policies, and cache performance optimization. Useful for GATE, IBPS IT Officer, university semester exams, and other competitive examinations.

Topic: Computer Organization & Architecture (COA) – Cache Memory | Set: 2

Difficulty: Medium to Advanced | Total Questions: 15

Cache Memory MCQ

Q1. In a direct-mapped cache, the number of bits in the “Tag” field increases if:

• A. Cache size increases
• B. Main memory size decreases
• C. Cache size decreases (keeping main memory constant)
• D. Block size increases

Q2. A system has a 32 KB direct-mapped cache with 32-byte blocks. For a 32-bit address, how many bits are used for the “Index”?

• A. 10 bits
• B. 15 bits
• C. 5 bits
• D. 12 bits

Q3. Which mapping allows a main memory block to be loaded into any line of the cache?

• A. Direct Mapping
• B. Fully Associative Mapping
• C. 2-way Set Associative
• D. 4-way Set Associative

Q4. Increasing the block size in a cache generally improves performance because it:

• A. Reduces miss penalty
• B. Takes advantage of spatial locality
• C. Reduces tag overhead
• D. Decreases the hit time

Q5. What is the disadvantage of increasing cache block size excessively?

• A. Tag bits increase
• B. Hit ratio always decreases
• C. Miss penalty increases as more data must be fetched
• D. Direct mapping becomes impossible

Q6. In a 2-level cache system, L1 has a 90% hit rate and L2 has an 80% hit rate. What is the global hit rate?

• A. 98%
• B. 90%
• C. 170%
• D. 72%

Q7. Which of the following is true for a “Write-back” policy?

• A. It is slower than write-through
• B. It reduces traffic between cache and main memory
• C. It ensures main memory is always up-to-date
• D. It is used only in ROM

Q8. A set-associative cache with 128 lines and a set size of 4 has how many sets?

• A. 512
• B. 32
• C. 64
• D. 124

Q9. The “Unified Cache” stores:

• A. Only instructions
• B. Only data
• C. Both instructions and data
• D. Only BIOS settings

Q10. In a 4-way set-associative cache, how many tag comparators are needed?

• A. 1
• B. 2
• C. 4
• D. 32

Q11. Which field in the address is used to select a specific byte within a cache block?

• A. Tag
• B. Index
• C. Offset (Word bit)
• D. Set

Q12. Conflict misses are most common in:

• A. Fully Associative Mapping
• B. Direct Mapping
• C. Write-back caches
• D. Multi-level caches

Q13. An L2 cache is generally:

• A. Smaller and faster than L1
• B. Larger and slower than L1
• C. Built into the CPU registers
• D. Located on a magnetic disk

Q14. What is the main advantage of Set-Associative mapping over Direct mapping?

• A. Simpler hardware
• B. Lower hit time
• C. Reduced conflict misses
• D. Faster tag comparison

Q15. The “Valid Bit” in a cache line indicates:

• A. If the data has been modified
• B. If the line contains a meaningful block
• C. The age of the block
• D. If the block is a blind write

Conclusion

These advanced Cache Memory MCQ questions help strengthen concepts related to cache organization, mapping techniques, multi-level caches, cache write policies, tag/index calculation, and cache optimization techniques. These topics are frequently asked in GATE, IBPS IT Officer, university semester examinations, and other technical competitive exams.

For better understanding, practice numerical problems on cache indexing, average memory access time, set-associative mapping, and multi-level cache performance.

Fore theory and concepts, refer to Cache Memory in Computer Organization.

What’s Next?

• COA Cache Memory MCQs (SET 1)
• OS Memory Management MCQs (Set 2) 
• OS Memory Management MCQs (Set 1)