What is the maximum number of workflow instances that a single workflow runtime can handle at the same time?
The maximum number of workflows that can run simultaneously in a single workflow runtime is the same as the number of CLR threads available for the process. Typically, this is 25 for single processor machines and 100 for dual processor or server machines. You can control the number of instances that can be run by specifying the number in the DefaultWorkflowScheduler constructor. The recommended number for single processor machines is 20.