Read Committed Snapshot Isolation and tempdb I/O Latency

SQL Server's Read Committed Snapshot Isolation (RCSI) is designed to eliminate blocking between concurrent read and write operations by utilizing row versioning. This mechanism shifts the concurrency burden from the lock manager to the version store located in tempdb.

In environments with high concurrency and frequent updates to large datasets, the overhead of maintaining these versions can introduce significant I/O latency. There is a critical trade-off between reducing lock contention and increasing the pressure on the tempdb subsystem, particularly regarding the allocation and cleanup of version stores.

When designing for high-throughput workloads, it is unclear how to optimally balance the tempdb configuration to prevent version store contention from becoming a larger bottleneck than the original locking latency.

• What specific tempdb configuration patterns best mitigate I/O latency when RCSI is enabled for high-concurrency workloads?
• At what threshold of concurrent update volume does the performance gain from reduced blocking get offset by version store overhead?