&gt; Those supposedly triple and dual core CPUs that got unlocked to quad cores were apparently a way to sell damaged silicon that the remaining cores passed QA so they just disabled the broken core.<p>It&#x27;s called &quot;binning&quot;, and it&#x27;s not just for defects. CPUs from the same chain can have different tolerances, one will reach 3.5GHz easy and the next one won&#x27;t be stable beyond 2.8. Those are also put in different bins and sold as different models.<p>&gt; Now, How much of that is true I don&#x27;t know but that&#x27;s what I remember reading at the time.<p>It&#x27;s completely correct. Selling a model from the exact corresponding bin is ideal, but if you have more demand than the bin provides you get parts from higher bins and gate them. A few years ago that got very very common with Intel parts as they reached tremendously low defect rates, and more or less any CPU you bought would come from the highest bins gated and undermultiplied to whichever model you&#x27;d buy.