Ants http://www.red-gate.com/products/dotnet-development/ants-performance-profiler/

If you have VS Ultimate, you can get the Load Test Feature Pack http://msdn.microsoft.com/en-us/vstudio/ff655021

Be aware that load testing and performance testing are different. Which do you need to do?

>Hi All,
>
>I have been pulled into a project that is having performance problems. I have some ideas to try and fix the problems but I need a good tool to load test the site so I can measure the changes. Anyone know of a good tool to use?
>
>Thanks.