At the time the validation models were not very mature so they moved everything up to higher metal layers with big-ass drivers and designed for worst-case. I'm

At the time the validation models were not very mature so they moved everything up to higher metal layers with big-ass drivers and designed for worst-case. I'm sure Intel has a much better handle on it now (they ain't dummies!), but back then the orders were "don't let the ring(s) throttle the cores".