The road to 3.5 Ghz should have a pitstop with about 8-25 hours of prime at 3 Ghz first.. how are you going for more when all it's stable to do now is superpi? I'm stable for over 20 minutes of 4 Ghz of superpi on my e6400, but it isn't useful for anything else.

I second the DFI Ultra-D as a new board.