[Everlag]

By disabled, do you mean the same processor design being binned into varying qualities of chip? In that case, it seems much more cost effective, and environmentally friendly, to send out chips with bad sections disabled at a lower price rather than to chuck them out.

[jacquesm]

More like 'disabled by scoring a large 'X' with a laser across the die for those features that are to be disabled'.

[rbanffy]

Yes, but only for those chips who would be binned in the high-end and go unsold.

And you can just design a couple on-chip fuses that can be broken in early stage testing. No need for lasers.