Hi, dren99 and BBBKKKSSS, I just checked the P4P800 SE motherboard's user guide. It says that this motherboard supports P4 478-pin package CPU with 512/256KB L2 cache on 0.13mm process. I checked my CPU spec., its part number is BX80546PG2800ESL79K, which uses 90nm process and L2 cache is 1MB. I think the 2 factors (90nm process and 1MB L2 cache) could be the problem that caused CPU overheat. Don't you guys think so?
I found there is another part number for P4 2.80G 1M L2 cache which uses 130nm process: BX80546PG2800E. There are 2 related links for your ref.
http://www.superwarehouse.com/BOXED_PENTIUM_4_2.8GHZ_HT_1M_800FSB_S478/BX80546PG2800E/p/360617
http://www.pcdirectsource.com/Item.cfm?ID=1517
So do you guys think I should replace the CPU to fit the motherboard or replace motherboard to fit the CPU? Thanks a bunch.