Moore's law is about circuit density. 1) Smaller circuits (used to?) have less capacitance and smaller voltages. Smaller voltages and capacitance enables hig

Moore's law is about circuit density. 1) Smaller circuits (used to?) have less capacitance and smaller voltages. Smaller voltages and capacitance enables higher clock-rate with same power consumption (chips don't melt) 2) Spending more transistors for pipelines and multiple execution units in the same core speeds up the processing. Single instruction takes at least five clock cycles from start to finish. With pipelines it's possible to finish one instruction per cycle. With multiple execution units it's possible to finish more than one instruction per cycle. This all from a single core. 3) Cache. Lots of it, different levels. Accessing external memory is very slow. Main cache reference takes about 1 ns. Main DDR MEMORY reference takes 100 ns. Waiting for 100 ns. wastes cycles. Adding prefetching etc. is yet another chunk of transistors.