I'm already working on 4.6GHZ for 24/7. It is going to be a big challenge to keep this cool&quiet, but getting it stable is not a little one, either.
I'm not sure if this wil work for 24/7 (yet), but it is always fun to push it to the edge, anyways.

@4.6GHZ (219x21) 1.36v SuperPi32M ... and work in progress ..