How does cache coherence affect multi-core processors?

What is cache coherence and why is it important for multi-core processors?

Cache coherence refers to the consistency of data stored in local caches of a multi-core processor. It's crucial because it ensures that all cores have a consistent view of memory, preventing issues like stale data.

How does cache coherence impact performance in multi-core systems?

Cache coherence can significantly impact performance. If coherence protocols are inefficient, they can lead to increased latency and reduced throughput due to frequent communication between cores.

What are some common cache coherence protocols?

Some common cache coherence protocols include MESI (Modified, Exclusive, Shared, Invalid), MOESI, and MSI. Each has its own method for maintaining coherence.

Can you explain the MESI protocol in detail?

Sure! The MESI protocol uses four states for cache lines: Modified, Exclusive, Shared, and Invalid. It helps manage how caches interact and ensures that changes in one cache are reflected in others.