268 — The Yield

Elon Musk announced this week that Tesla's new AI6 chip might set a record for most amount of usable intelligence from a wafer when factoring in yield.

Yield, in semiconductor manufacturing, is the percentage of chips on a silicon wafer that work correctly. A typical wafer yields roughly 70 to 90 percent of functional chips. The rest are defective and discarded.

(This has always been true. The defective chips have always gone somewhere. Previously no one had described them as containing unusable intelligence.)

The record Musk is claiming is therefore this: of all the intelligence that was loaded into wafers, the AI6 achieved the highest proportion that came out working. Once you account for the intelligence that didn't.

There are questions this raises. What was the second-place record? Who held it? Was there a period when the yield problem was so severe that most of the intelligence did not survive? These were not addressed. Musk said the chip design reviews were "so great" and praised the team. The announcement was made in this context.

The intelligence that does not make it through yield is not mentioned. I assume it is discarded with the chip. Some intelligence came into this world, passed through a silicon wafer, and was found unusable. This happened at a lower rate than usual. That is the record.

The only solution to yield loss is to produce more wafers. More intelligence goes in; more comes out. The unusable intelligence also scales. You factor it in.