Consider writing your application in something else than .NET and consider using a fast database server.

I know C# is a really great language, but when executing managed code the whole thing slows a bit down. Try using C++ to get enough speed on the client side, and try to get a really fast database server.

And also.. consider deleting as many indexes from the database as possible. Every index entry speeds up select statements, but slows down inserts

greetings UNI