ADO.NET makes big steps to improve performance with its disconnected recordset model. There is no doubt that working with a cached DataSet object will increase performance by allowing multiple tables to be stored and manipulated from a single query. However, the biggest advantage of ADO.NET will be its use of XML. This can easily be seen in a distributed application environment. Using XML rather than COM marshalling provides big performance advantages by eliminating the architectural restrictions required by COM. Because XML is text-based and has a strong industry backing, the penalties of converting a recordset to usable data that can be recognized by COM do not have to be incurred. Any component that uses XML can receive XML data provided the schemas are identical.
ADO.NET is also lean when your ADO code accesses information from a database. It stays lean by keeping minimal table locks and minimizing connection times. The result is higher performance without additional hardware. This is especially important in a Web-based application where loads can increase rapidly . As the number of users increases , the system resources needed to maintain that load increase by a small fraction.