There are some things you can do to optimize your query. Here on MSDN you can find a nice overview.
But to be honest, a stored procedure with manual mapping will always be faster in performance. But ask yourself, how important is performance? In most projects, development time is way more important then performance. What was harder to develop? The raw query with parsing or the Entity Framework query?
ORMs are not designed because they perform so much better than a hand written approach. We use them because development is so much easier!
If you write your application with the Entity Framework and hide all your queries behind a repository pattern you can develop real quick and then, when performance becomes an issue, measure your application to detect the bottleneck. Then maybe some of your queries need optimization and can be moved to stored procedures and manual mapping.