>but since microarchitecture is in large parts dictated by ISA Well, Apple uses the ARM ISA for their A and M series chips, and but not ARM's microarchitecture

>but since microarchitecture is in large parts dictated by ISA Well, Apple uses the ARM ISA for their A and M series chips, and but not ARM's microarchitecture, and their chips have significantly higher IPC than comparable parts from Qualcomm or Samsung. Similarly, Intel and AMD both implement the same x86 ISA, but the performance advantage has swung repeatedly between the two. Microarchitecture might be "in large parts" dictated by the ISA, but there's still enough left over for hardware designers to have a significant influence on the overall performance.