Quite contrary. Chip harvesting allows imperfect processor dies to be sold as otherwise fully functioning processors. If you own a Core i7 or i5, or a Ryzen 5/Ryzen 9 x900 series, you have a harvest in your hands.
Sure, but as the process matures, yields improve all the time. No one is willing to disclose any specific data, just some relative info like in this example graph (let's assume it's zero-based):
And then there are estimates by analysts such as
TrendForce:
At present, the production yield rate of Sapphire Rapids is estimated at only 50~60%, which affects mainstream Sapphire Rapids MCC products. [November 2022]
which doesn't tell us the most basic thing - are the bad chips totally unusable, or do they just have a small number of bad cores out of 34?
2.5 years into Intel 7 manufacturing, I'd say it would be
very bad for Intel if less than 50% of the CPUs on a Raptor Lake wafer were operative - I mean fully operative, with zero defects. They can't sell that many i9-13900/14900 chips (despite countless suffixes) because those all cost 440€ and up. So they still have to disable some good parts.
CPU manufacturing is a very complicated process, and imperfections can be present in any area of the processor. This one has the four e-core clusters and associated L2 cache disabled. What's interesting is that the full L3 slice is enabled on the 14901KE, which may mean that the L3 cache that is normally attribute to an e-core cluster is not necessarily an inherent part of it and can be accessed by the P-cores normally.
The same is true of the other chips in this new series, see my post #42. Interestingly, the two disabled P cores in the 14501E also have their L3 slices inoperative.
the failures don't exactly follow a neat pattern. Which is why is we need some communication from intel. All we seem to know for sure is that higher clocks and higher voltages make it worse/speed it up, whatever the root problem is, maybe there's more than one root problem.
Exactly. I'd even suspect the power delivery system on the chip (and substrate too) first, which would mean that you can't pin the flaw to any of the cores.