Guys, it is nice that somebody re-opens that issue in general. Originally I used to have exactly that idea in mind but digging in to the problem with quads unlocking (on ATI based cards) I become not so confident in that idea. For sure resistors configuration is one of the methods for locking / unlocking and so on but ATI did something different at least on R420, R423, R430 cores but I am almost sure that on R480 is the same. If that issue is interesting for you, please see that http://forums.techpowerup.com/showth...1&page=1&pp=10
and probably you can contribute with something
About laser cuts on the back side of the core - yes it is true and you can see it also at the provided link.