As far as I know, P4 CPU’s have always been locked to a certain multiplier. Overclocking is limited to FSB overclock.
But I just found a manual for one of my old RD-RAM motherboards and it has a Switch to select a multiplier for both 400 and 533Mhz busses. It goes from 16x to 24x (400Mhz FSB) and 16x - 23x (533Mhz FSB)
Are there unlocked P4 CPU’s? Or is it a useless feature? Of course it’s not a big deal to test it, but I just wanna hear some opinions first