What is the relationship between latency and bandwidth in cache coherence?

What is the relationship between latency and bandwidth in cache coherence?

Latency refers to the time it takes to access data, while bandwidth is the amount of data that can be transferred in a given time. In cache coherence, low latency is crucial for quick data access, while high bandwidth ensures that multiple processors can communicate efficiently.

How do these factors affect system performance?

High latency can lead to delays in data retrieval, causing performance bottlenecks. Conversely, high bandwidth allows for faster data transfer, improving overall system efficiency, especially in multi-core processors.

Can you give an example of a system where this is critical?

Sure! In multi-core processors used in servers, maintaining cache coherence is critical. If one core updates a cache line, others need to access that data quickly to avoid stale data, making low latency and high bandwidth essential.

What techniques are used to improve cache coherence?

Techniques like directory-based coherence, snooping protocols, and cache coherence protocols such as MESI (Modified, Exclusive, Shared, Invalid) are commonly used to enhance cache coherence.