The new replication algorithm in ScyllaDB is called "Tablets" and it promises to offer faster read/write speeds, better consistency guarantees, and improved fault tolerance. The traditional master-slave architecture used by most databases has some limitations when it comes to handling large amounts of data or high write loads, which can lead to performance issues and downtime. With Tablets, ScyllaDB aims to address these challenges by using a distributed key-value store that is optimized for high availability and scalability.