Parallelism Cost Threshold

The parallelism cost threshold is a setting that SQL Server uses to determine when to run a query using multiple threads. Setting it too low can cause the query optimizer to spend more time planning how to run queries using multiple threads, rather than running the query itself. Setting it too high threshold could cause SQL Server to only ever run queries in single threads, potentially causing slower performing queries.

Suggested Action

Consider increasing the parallelism cost threshold.

Any suggestion from Aireforge should be thoroughly tested before being implemented into production.

Further Reading

VMWare recommend a setting of 50 | Architecting Microsoft SQL Server on VMware vSphere®

PureStorage recommend 15-20 for OLTP and default (5) for OLAP | Pure1 Support

Tuning ‘cost threshold for parallelism’ from the Plan Cache | SQLskils