You learn something new every day... Do you have a source for this? I'd like to read more on it.
I'm sure it has been written about somewhere in the public domain (since you could see the fuses if you were looking hard enough), but I can't find a source on google with some quick checking. It's probably in the past parts were actually laser defeatured to prevent overriding fuse/eeprom bits. No idea what AMD was doing that allowed mobos to re-enable the 4th core on 3 core chips. Probably passing out the fuse read values through to the chipset and then the bios was making a decision on what cores to use.
EDIT: I think "Polycrystalline silicon fuses" is what the technical name is, for further research
Edited by dr/owned - 4/10/13 at 11:26am