What are the differences between directory-based and bus-based cache coherency?

What are the differences between directory-based and bus-based cache coherency?

Directory-based cache coherency uses a centralized directory to track the state of cached data, while bus-based relies on a shared bus for communication.

Which method is more efficient in a multi-core processor?

Directory-based is generally more efficient for larger systems as it reduces bus traffic, but bus-based can be simpler for smaller systems.

Can you explain how each method handles cache misses?

In directory-based systems, the directory helps locate the data in other caches, while bus-based systems broadcast requests on the bus to find the data.

What are the advantages of using directory-based cache coherency?

Advantages include reduced bus traffic, scalability for larger systems, and better performance in multi-core environments.