The 12GB, artificially locked, would be only the first batch of them. If there's no need (AMD can't compete), the manufacturing would switch to genuine 10GB, limited bus models, which would be cheaper to make (and obviously can't be unlocked). However, if AMD can compete, Nvidia will need to swallow its tears, unlock the early cards, and have future production be 12GB straight out of the factory. So, Nvidia would only be using a plot like this for the chance it might be able to save money in the future. The future GPU chips would have "extra" memory controllers disabled, so OEMs couldn't make their own fancy versions. Before that, I guess Nvidia would just forbid it. It's not like the custom card manufacturers could go against Nvidia's rules if they want to receive the GPUs.