OK I reset.
I had issue with performance but I think it's not grirdview.
I used LinqtoSQL with storedProcedure.
I get IEnumerable object (9000 rows and 10 fieds), it's faster
But when I Put the result to RadGridView.DataSource that take more 60 seconde !
I tested with transform IEnumerable -> ToList , it's the problem.
Have you a solution ?