Jes Borland shows how to use ostress to perform load testing against a SQL Server instance:
Ostress allows you to specify one file, or a folder that contains multiple files, to run. You can also specify a number of connections to be made to the database, to simulate multiple users or applications running the same query. Each connection can then run the file one or more times.
The next thing you’ll need is one or more .sql files that the tool will run.
To run a load test, you’ll open RML cmd prompt and enter your command.
Ostress isn’t as nice as a replayable trace for generating production loads, but it’s an easy method to stress test a server.