Yes, fine tuned and fast caches is what Apple was going for last few generations. AMD Ruzen also got much faster caches than their previous gen chips. Most importantly, fined tuned caches don't come as a power/performance trade-off - they are simply better.
Moreover, when litho generations progress to 10nm, the difference in power consumption in between working and non-working transistors gets so small, that the traditional convention that "a slow chip is also a low power chip" does not hold true. You are better off in regards to power consumption if you get your IPC up and IO-wait down.
Moreover, when litho generations progress to 10nm, the difference in power consumption in between working and non-working transistors gets so small, that the traditional convention that "a slow chip is also a low power chip" does not hold true. You are better off in regards to power consumption if you get your IPC up and IO-wait down.
The best analysis of A12 cache performance I know of that is written in popular language is this piece: https://www.anandtech.com/show/13392/the-iphone-xs-xs-max-re...