Resource and space requirements for temporary databases vary from application to application. You should size all temporary databases equally unless you:
Fully understand your resource and space requirements
Maintain applications to database and group bindings so that database assignments meet resource and space requirements
By sizing all temporary databases equally, you should be able to run applications without running out of resources or space, regardless of which database gets assigned to a given instance of an application or session.
Similarly, configure the tempdb caches within a group similarly to ensure equivalent performance for a given query plan regardless of the tempdb used.
In high-availability configurations, configure the primary and secondary servers similarly with respect to tempdb properties.
