For more than 50 years, designers of computer chips mainly used one tactic to boost performance: They shrank electronic components to pack more power onto each piece of silicon.

Then more than a decade ago, engineers at the chip maker Advanced Micro Devices began toying with a radical idea. Instead of designing one big microprocessor with vast numbers of tiny transistors, they conceived of creating one from smaller chips that would be packaged tightly together to work like one electronic brain… (read more below):