Michael S (already5chosen.delete@this.yahoo.com) on February 8, 2015 5:38 am wrote:
> I'd don't know what changed within ARM application processor group, but recently they have very high success
> rate: A7, A12, A53, A17 are all pretty good.

Focus on incremental improvement maybe? A8, A9 and A15 were all big jumps with significantly different micro-architectures than their predecessors. All of the ones you listed on the other hand have evolved from previous cores. They have better branch prediction, tighter coupling of the L1/L2 caches and other improvements which do not significantly affect the execution core yet provide very significant benefits, and especially so in integer codes. Most of those improvements can also be shared between the cores so that might also have helped out in focusing development efforts.