Question

Which of the following models has the most stringent consistency requirement and is also called the strongest form of memory coherence?

• A. Sequential Consistency
• B. Strict Consistency
• C. Causal Consistency
• D. None of the above

Hint:

Strict consistency is the strongest memory model, ensuring that every read returns the most recent write globally, but it is difficult to implement in real-world systems.

Answer 1

The Correct Option is B

Step 1: Understanding Memory Consistency Models A memory consistency model defines the order in which memory operations appear to execute across different processors in a distributed or multiprocessor system.
Step 2: Strict Consistency - The Strongest Model
- Strict consistency ensures that every read operation returns the most recent write, regardless of processor location.
- It provides absolute memory coherence but is impractical to implement due to high overhead in distributed systems.
Step 3: Evaluating the Options
- (A) Incorrect: Sequential consistency maintains program order but allows different processors to see operations in different sequences.
- (B) Correct: Strict consistency is the strongest form of memory coherence.
- (C) Incorrect: Causal consistency ensures that writes related by causality are seen in order but does not guarantee global coherence.
- (D) Incorrect: A correct answer exists in the given options.