> with many-core, having to budget decoder silicon/power might start to matter enough That seems backwards to me. Narrower, simpler cores with fewer execution

> with many-core, having to budget decoder silicon/power might start to matter enough That seems backwards to me. Narrower, simpler cores with fewer execution engines have a much easier time decoding. It's the combinatorics of x86's variable length instructions and prefix coding that makes wide decoders superlinearly expensive.