Your data doesn’t cover a very important problem: Apple cheated to get their performance.
Architecture lock-in is a very real software problem. It’s one reason for using Java code in Android and is the reason why Google specifically targets 3 different ISAs. While the ARM lock on mobile isn’t near as strong as the MS and x86 lock on desktops, it is still very strong.
Even when better chips were available (eg. MIPS proAptive which was faster, half the die area, and lower power than A15 with better coremark performance), the market still chooses ARM showing that the lock-in is real. With ARM, that’s not a terrible situation because you can either purchase their designs or create your own as long as you pay them – companies definitely prefer this to x86.
If you aren’t familiar, it takes 4-5 years to create a new CPU architecture, test/verify it, and tap it out. Not even the most powerful players in the game like Intel or IBM can beat this (they instead overlap design teams to keep the changes flowing). ARMv8 launched in Oct 2011.
Apple managed to not only tap out, but ship a chip using the new ISA in TWO years. Either PA Semi had super-engineers or something strange is going on. ARM’s simplest design (the A53 – based on an existing micro-architecture) didn’t ship until late 2014 and their “high-end” A57 didn’t get out the door until 2015. A57 is a poor design with a lot of issues indicating it was rushed out the door.
A72 (shipping mid 2016) is a fixed version of A57 with a lot of improvements that had to be sacrificed to get A57 out the door and it should come as no surprise that the fixed version finally starts to catch up with Apple’s design from 2013. Qualcomm is also taking 5 years to launch their ground-up redesigned processor (Snapdragon Kryo). Samsung’s custom core also doesn’t arrive until next year. Denver managed to catch up part-way, but only because it’s a transmeta-based design and the biggest changes were to the firmware (and it’s been in progress for years – originally intending to get around x86 patents until they struck a deal with Intel).
If you ask around at these companies, pretty much everyone was beyond shocked when Apple not only launched with only 2 years time, but the chip was actually good. After all, ARM would run afoul of quite a few laws if it could ever be proven that they had given Apple a head start. How did Apple do this? How did a third-party launch 3 years before ARMs own A72?
Apple’s changed ISAs before (POWERpc to x86) and it’s not easy (especially when all the code is native). Apple also has some loose ties to ARM since they co-founded the company in the 90s (they sold the shares in the early 2000s, but that’s not the only important thing in business). With x86 being a one-horse race (AMD has basically been out for years), Apple needs a different desktop ISA.
MIPS was on the market and is a great ISA. The only problem is switching from ARM would be a big problem. Instead, it would be nice if ARM would simply clean up their ISA which they did. The resulting ISA is extremely similar to MIPS and perhaps explains why ARM was so keen to spend hundreds of millions to get access to the MIPS patent portfolio after Imagination bought them.
The rest is supposition based on these (and a couple other) facts. Apple was one of the big companies rumored to be looking at getting MIPS. They start building a micro-architecture with a MIPS-like ISA in mind. They then come up with a cleaned-up ARM ISA that is very similar to MIPS, so they can continue work and go either direction late in the design game (in fact, they could probably design both control blocks at the same time as the micro-arch and the uncore would remain unchanged).
All thats left is to talk to the ARM guys. Either ARM loses one of their biggest, most influential customers or they negotiate to adopt the new ISA. Apple has around 18 months to finalize and tap out with another 8 months to ramp up for the new launch. This also explains ARMs rushed A57 and the much longer delay by the other companies.
The big win for Apple is that they outmaneuver their competitors for at least 2 years and most likely 7-8 years.