A draft release of the PostgreSQL 13 release notes is available. Notable changes include:
- Better support for partitions.
- Improved streaming replication and recovery.
- Allow auto-vacuum to process indexes in parallel.
- Many other performance improvements.
The pg_bench utility is one way to measure the performance of a new version of PostgreSQL (it has been improved to benchmark partitions). Your actual systems that run on PostgreSQL would need to be benchmarked separately.
See also: PostgreSQL Books