get a cooler i got one for mine $40 AUS i got it to 4.24Ghz but on a normal warmish day 4.0Ghz it was my first overclock it runs every day with no trouble pentium d 915 overclock very well but if you really want to use your stock cooler i'd say take it to 3.2 in steps, small steps dont touch the voltage though eventhough there a cooler cpu. what board you using?????? what ram????????? have you ever overclocked before?