Explanation:

Snoopy writes:
- Snoopy write is an efficient method of cache updating where the cache controller monitors or snoops the bus for write requests to main memory.
- When a write request is detected, the cache controller updates the corresponding cache line to ensure data consistency between the cache and main memory.
- This method helps in keeping the cache coherent without the need for the processor to intervene in the write process.

Write through:
- Write through is a caching strategy where data is written to both the cache and main memory simultaneously.
- While this ensures data consistency, it may lead to performance overhead due to the additional write operations to main memory for every write request.

Write back:
- Write back is a caching strategy where data is only written to the cache initially, and the main memory is updated when the cache line is replaced.
- This strategy can be more efficient in terms of performance compared to write through, as it reduces the number of writes to main memory.

Buffered write:
- Buffered write is a technique where write operations are first stored in a buffer before being written to main memory.
- This can improve performance by allowing multiple write requests to be batched together and sent to main memory in a single operation.
- However, this method may introduce additional complexity and potential risks related to data consistency.

In conclusion, Snoopy writes is considered an efficient method of cache updating as it helps in maintaining cache coherence without significant performance overhead.