You may be pointing the finger in the wrong direction when you accuse your data access middleware of causing performance problems. The design of your database governs performance to a much greater degree than your choice of database access middleware.
Most databases can benefit from changes in table design, choice of index columns and query design.
If you focus first on these areas, you'll reap the most rewards from your efforts to make your database perform faster. Normalizing the design of a database entails the elimination of redundant data, the avoidance of repeating data groups and the creation of separate tables to hold different categories of data. A properly normalized database generally has many tables with relatively few columns in each. Simplifying long-running queries through the use of appropriate keys and indexes can reduce response times, and you might consider running complex queries that look at entire tables during times of the day when transaction volume is low. Normalizing the database, along with using SQL that's as simple in construction as possible, helps the SQL compiler portion of the database server process faster.