> This became an easy decision [in 2015] for Apple to ditch Intel when they saw how much better their own iPad Pro was relative to the 12” Intel MacBook.
[1] implies that the M1 development started around 2008 - although you could also read it that the M1 was 5 years in development but that sounds a bit quick and also doesn't fit with [3] in 2014 - "Apple Testing ARM Based Mac Prototypes".
But there doesn't seem to be any other direct corroboration of the 2008 date that I can find.
2008 is probably about the time Apple started serious work on in house CPU cores, rather than specifically the M1? The A6 chip was the first with an Apple designed core, and was released in 2012, so they would have been working on it for several years before.
[1] implies that the M1 development started around 2008 - although you could also read it that the M1 was 5 years in development but that sounds a bit quick and also doesn't fit with [3] in 2014 - "Apple Testing ARM Based Mac Prototypes".
But there doesn't seem to be any other direct corroboration of the 2008 date that I can find.
[1] https://www.youtube.com/watch?v=4oDZyOf6CW4 via [2] [2] https://news.ycombinator.com/item?id=31778257 [3] https://www.macrumors.com/2014/05/25/arm-mac-magic-trackpad/