David Klee has a couple of articles about load-testing. That is – running software utilities to simulate various kinds of load on SQL Server and the horse it rode in on – the Server. Since we can have SQL in VMWare\HyperV and VMWare Player can run on a linux box, the server as hardware or as the OS is not strickly defined. Whatever.
Now, as you run these things (and collect the typical output) you can also start monitoring extended events to look at what MS SQL is doing as I/O or stress levels change.
Mike Fal has a blog post on putting “lines in the sand” (my capitalization, not his). withing with HammerDB.
Brent Ozar champions Adam Machanic’s SQLQueryStress application that runs multiple sessions of a random selection of stored procedures