Long ago, we published “Apple’s Planned Obsolescence Schedule” (2 November 2011), an attempt to determine the number of years different versions of macOS and iOS maintained backward compatibility. Over at Ars Technica, Andrew Cunningham has now taken a swing at the topic from a different direction, trying to determine how many years Macs receive macOS updates and if that’s changing over time. He shows that the number of years that Macs received updates fell from 1999 through 2004, increased until about 2012, and then dropped again through the end of the data in 2016. The first dip matches the transition from PowerPC to Intel chips, and it seems likely that the recent downturn is related to the move to Apple silicon. The question is if the chart will start to trend back up once Intel chips have joined 68000 and PowerPC processors in the depths of Mac history. Interestingly, the average Mac receives 7 years of macOS updates from the date it’s introduced, plus another 2 years of security updates.