In theory, you can but we're talking on a nanometer scale. It very well may happen this way. I haven't paid attention to processor designs in the last few years. I just don't see this being very practical.Sure. But what usually happens is that you take the die and then blow fuses to disable / enable various optional features or turn off failed sections. So you could (again, I don't know what Intel are doing, but this is the way other people do it) fab a wafer containing identical parts, but then some of which end up being configured as i7s and others being configured as i5s.
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I've been meaning to add this for a few days...
In memoriam... the Original X-box...
From a different view...
