Just look at the voltage ratings for this 0,13µm pentium4 processor.. "SL793"
might be able to clock easily up to 4ghz.
http://processorfinder.intel.com/sc...am=483&PkgType=ALL&SysBusSpd=6107&CorSpd=6135
might be able to clock easily up to 4ghz.
http://processorfinder.intel.com/sc...am=483&PkgType=ALL&SysBusSpd=6107&CorSpd=6135