You some day will face the following problem: your queries have turn out very slow, having SQL Server so many components, you need to start checking some basic points. You can start checking out the following DMV:
These DMV will give an idea where all the server resources going. If you want you can focus on dm_os_wait_stats that will give an idea to start the diagnostics to find the performance bottleneck.
Eduardo Castro Martinez
Microsoft SQL Server MVP