YugabyteDB outperforms CockroachDB in a comparison of their performance using the YCSB benchmark, achieving 3x higher throughput and 4.5x lower latency on average. YugabyteDB's storage layer, DocDB, is engineered for high performance at scale, with smart load balancing across multiple disks, separating compaction queues to reduce read amplification, and enabling multiple RocksDB instances to work together efficiently on a single node. In contrast, CockroachDB's storage layer is simplistic, leading to poor performance in large-scale workloads. YugabyteDB's query layer reuses PostgreSQL's native query layer, retaining advanced RDBMS features and allowing application development velocity to remain uncompromised. The comparison highlights the importance of considering the design principles and architectural differences between distributed SQL databases when evaluating their performance for specific use cases.