I have a Dell Dimension 8400. It has a Pentium 4 540J 3.2 mhz socket 775 Prescott processor. The mother board is a Dell with an Intel Alderwood i925X chipset Southbridge 82801. I would like to know if I could upgrade to a Intel Core 2 Duo E4700 2.6 ghz CPU. If that would work how much higher could I go and still have it make sense?