i'm upgrading my chip from a 1.7 p4 to a 2.8 p4.. now, the motherboard says it can go up to a 3.0 p4.. does this mean that the heatsink can handle a 2.8? or is there no more heat coming from the 2.8 than is coming from the 1.7? thanks for your help..

Your 1.7 P4 is a Willamett core with 1.75 default volt, while the P4 2.8 is Northwood core with 1.525 volt. Depends on which 2.8 you have; 533 or 800 mhz they both are running any less heat than the 1.7 due to increase in speed.

The retail pack Intel heatsink will handle the heat easily. The question remains that a good heatsink does not mean anything when the case ventilation is poor. A front intake and rear exhaust are must have in keeping CPU cool nowadays.