I have an old Athlon XP 1900+ (Palomino), and tried to unlock it. My MB is Gigabyte GA-7N400E. When i put the multiplier to 12.5 (default is 12x133), BIOS recognizes it like 12, and when multiplier is on 11.5 BIOS says 11 (cpuz also says 11x133) ?!? Should i consider the CPU is unlocked or try again ?
Try placing the multiplier at 13 and see if the BIOS allows it to go above stock. Kinda odd though that it doesnt seem to like half multis. I had a similar processor xp 2700 and could never get it to unlock properly. Good luck.
Palominos were locked, but there were some unlocking techniques with tape and bridging with silver grease or epoxy, but that was awhile back.
Old Thunderbirds could be unlocked with the pencil trick, but Palominos and Thoroughbreds and Bartons were much more difficult to unlock the multi on.
During that time there were a couple of M/Bs if I remember correctly that could themselves unlock the multiplier, but I can't remember which ones it was maybe the ASUS A7N8X Deluxe or something like that, crap I don't remember exactly.