Apple doesn&#x27;t want their own ISA. MIPS was going for a song just a couple years ago and Apple decided not to buy. That was the best shot they&#x27;ll have at their own ISA (they could go with RISCV, but they wouldn&#x27;t own it).It is my belief that they got what they wanted by forcing ARM to switch to the ARMv8 ISA.<p>New microarchitectures take 4 years or so to design. ARM announced the new ISA in 2011 and didn&#x27;t have a shippable product until 2015 which is very typical. All the other implementers (eg. Qualcomm) have also not been able to ship until now (Qualcomm&#x27;s custom Kryo doesn&#x27;t hit until later this year). Apple shipped a better product in 2013 than A57 is today (ARM doesn&#x27;t catch up until A72 later this year). To my knowledge, a licensee had never shipped a new ISA before the ISA designer up to this point. How did they get a chip designed, validated, tapped out, produced, integrated, and shipped out in 2 years?<p>I believe that Apple looked into purchasing MIPS or designing a custom ISA, but was put off by the costs and headaches associated with moving ISAs (having already done this with the change from POWER to x86). Instead, they design an ISA that is incredibly close to MIPS and start implementing a micro-architecture. Once they reach the stage where they must make a decision about which ISA, they tell ARM to use their ISA or they will move to MIPS. This head-start also<p>ARM is already somewhat threatened by Android having first-class support for MIPS. Having such a big player switch would be extremely threatening to them. The result would be an immediate caving. ARM would need to publish the ISA, but Apple would have a couple year head-start on implementing it (this head-start also puts Apple in a good competitive position relative to Android phone manufacturers). The rest is observable history.<p>This may not accurately represent what really caused this series of events, but it does explain why Apple got a good chip out before ARM could release a bad one (ARM couldn&#x27;t even get a smaller, easier chip out the door). It also explains why all the other chip companies hint at their surprise at Apple&#x27;s early launch.