Used to have a P3 that i OC'ed from 500 to 700Mhz. Could go higher even though at stock cooling it was 37C-45C depending on load. Never bothered as it was a bit risky with a crappy PSU.

My current rig is not OC'ed. Only pushed the GPU with ATITools. Won't dare OC'ing my AMD XP2500+ even with my Coolermaster Aero7+ installed. Temps now are around 53C with no load.

And i believe Bartons like my XP2500 are extremely overclockable. The FSB can be pushed from 166 to 200.

Pushing to the limit would be better.