Couchbase Server 3.0 introduces the Database Change Protocol (DCP), a significant enhancement for data synchronization that underpins various functionalities such as maintaining replicas, rebalancing, node recovery, backups, indexing, and XDCR replication. Unlike previous versions where XDCR replication relied on disk persistence to detect mutations, version 3.0 leverages DCP to initiate a direct stream for mutation detection, significantly reducing latency by up to four times through faster streaming and memory processes. This improvement enhances high availability and disaster recovery by accelerating data transfer to remote clusters, offering better protection against regional disasters and improving global data availability for deployments. While performance improvements are notable, actual latency can vary based on factors like network bandwidth, ping latency, and computational capacity, prompting users to test Couchbase Server 3.0 for the most accurate assessment.