Can you link an analysis for that where small cores have more perf-per-watt then a clocked down big core? From what I understand the transistors aren't mostly

Can you link an analysis for that where small cores have more perf-per-watt then a clocked down big core? From what I understand the transistors aren't mostly for enabling the higher clock speed at all, they allow for wider cores that do more per cycle. It doesn't seem clear at all that they would be less efficient than a narrower design that does less per cycle, if clocked much lower to yield the same final performance per cycle.