Considering I'm someone who knows very little about hardware and almost nothing about its manufacturing process, I have a question.

I assume what this article means is that only 55% of the produced chips in this process node are considered completely working, which I suppose it means that these 55% of chips are the ones who must have passed all the tests.

So that leaves 45% of chips where at least one defect was found. But here's my question: with Apple's M2 Ultra chip having 134 billion transistors, do the tests really cover all of the non-redundant transistors, which I assume are a substantial portion of them? And also, even for those transistors that are tested, how reliable are these tests in detecting defects?

And assuming that not all transistors are tested, given that 45% is such a high failure rate, isn't there a very high chance that even those chips that passed all the tests also contain plenty of bad transistors, but they simply weren't tested (or even if they were tested, the tests may have not reliably detected a fault)?

Even considering that these chips contain some redundancy / fault tolerance, it just seems kind of amazing to me that they are as reliable as they are given all the unknown faults that they might have (and I'm only focusing on the manufacturing process, but some of the same reasoning also applies to the design).

Achieving 60% yield on the first GAAFET node in the entire industry is a pretty big accomplishment for Samsung.

Silly question: is this reasonable or unreasonable from Apple? I could see it going either way.

I wonder how this compares historically for new process nodes, and vs. mature process nodes?