i have hit a barrier

here is my dilemma. i have a 2.8C Northwood with stock cooling and a thermal pad that came with the stock cooler. I have managed to get it to 236 FSB (3.3ghz) stable with no hiccups, however if I try to push it to 243 FSB (3.4ghz) I crash when I try to run games or do anything that stresses it. I know my ram can take it, I have 2GB of Crucial Ballistix DDR500 so I know 250FSB should be achievable. However, when I open Speed fan, I don't see any change in VCore (1.6) and very little in temperature (jumps maybe 2ºC, stays idle at around 26ºC with the AC/Air Purifier on).

my question is, is my mobo temp reader wrong and is it really overheating? or is my board just limiting my OCing capabilities?

Some 2.8C processors will only do 3.3 to 3.4 gig. What mobo do you have?

check the temps with a probe if you can, or touch it after some load to see if its hot. if its ocd, it doesnt seem that those temps are right. Unless you are getting alot of airflow. Whats the ambient temp in your room?

i have an asus p4p800SE flashed to bios 1009.

psu is aerocool aeropowerIISE 550w

i have a lian-li pc65b case with 2 intake, 2 exhaust (3 if you count the pci exhaust) 80mm fans and the cabling is neat and tidy. ambient temp in my room is 60-65ºF.

Make sure you have the AGP/PCI locked to 66/33. Those Asus motherboards are notorious for drooping voltage under load. Run a benchmark and check the vcore while you are doing it. Let us know how much it drops. If it's a significant amount, maybe try one more bump in voltage.

i switched the agp/pci to 66/33 from 'auto'. when at 240 FSB (stable) the voltage sticks at 1.6-1.62 but when i load it with 3dmark or CSS I see a drop down to 1.565-1.575

Sounds like your CPU is borderline max. Maybe one more bump in voltage will help, but I wouldn't go anymore than one more notch.

couple things:
1. these mobos are known for understating the temps, so add about 10C for more accurate temps
2. test ram with memtest86 and cpu with dual prime95 for solid results
3. what vdimm are you using ?

D