On Tue, Sep 12, 2017 at 5:21 PM, mike.valk@gmail.com mike.valk@gmail.com wrote:
Small defects hinder speed. Thus sell them with a lower speed rating. That's why overclocking yields different results for different cpu's the CPU's are sold batched on the lowest common.
With bigger defects they can overcome by adjusting microcode to compensate.
With the rise of multi core. Defect cores are disabled and those CPU's are sold as cpu's with less cores. Sometimes you can get lucky and can re-enable core's.
So same CPU is sold in different guises. Just according to quality and sometimes demand.
In theory this is correct, in practice, at least on the x86 area intel's desktop cpus are mostly quad cores, and on laptops all the dual cores so far have been SoCs with the chipset on the die, while the mobile quad cores were not. So it's not possible for intel to ship dual cores derived from quadcores. On gpus this is common practice, to the point that I remember some amd card that some cores were disabled via firmware which people just flashed to reenable them with varying success given that in most cases those cores were disabled for a reason.