>Chances are you can't just give the A13 a 95W power budget and see it hit 5GHz, it would have to be redesigned and the kinds of changes necessary to get there would generally lower IPC.
It's not really a difficult concept to understand. If your CPU runs at 5GHz then maximum time a single cycle is allowed to take is 0.2 nanoseconds. CPU designers have to make sure that this limit is never exceeded anywhere on the chip. If you make a even the slighted mistake in some unimportant corner of the CPU you will end up limiting the maximum performance of the entire CPU.
Most CPUs are optimized for a specific clock frequency and going beyond it is not possible without sacrificing stability.
It's not really a difficult concept to understand. If your CPU runs at 5GHz then maximum time a single cycle is allowed to take is 0.2 nanoseconds. CPU designers have to make sure that this limit is never exceeded anywhere on the chip. If you make a even the slighted mistake in some unimportant corner of the CPU you will end up limiting the maximum performance of the entire CPU.
Most CPUs are optimized for a specific clock frequency and going beyond it is not possible without sacrificing stability.