Core i7 could be overclocked quite easy! Even to 5GHz on a quad! Simply unbelievable!
Check http://uneit.com/2008/11/02/intel-core-i7-at-5ghz/ for pic.
Check http://uneit.com/2008/11/02/intel-core-i7-at-5ghz/ for pic.
Northwood P4s overclock well, especially with their lower (1.5v default) voltage. Lower voltage means reduced power consumption and less heat generated, which translates into improved stability.