When executing a stored procedure, what is the benefit of using CommandType.StoredProcedure versus using CommandType.Text?

So in C# to use a stored procedure I have code like the following (connection code omitted):

 string sql = "GetClientDefaults";

 SqlCommand cmd = new SqlCommand(sql);
 cmd.CommandType = CommandType.StoredProcedure;    //<-- DO I NEED THIS??
 cmd.Parameters.AddWithValue("@computerName", computerName);

Where sql is the name of a stored procedure. Now, this code seems to work just fine with and without the commented line.

So, do I need this line? Is there some performance (or other) benefit to setting this? Is there a benefit to NOT setting it or setting it to Text?