The Connection Machine CM-1 had 65,536 processors

The Computer History Museum’s catalog entry for a Connection Machine CM-1, built by Thinking Machines Corporation in 1985, records that a full configuration contained 65,536 one-bit processors - sixteen processors per chip across 4,096 chips - arranged in a twelve-dimensional hypercube. The machine’s panels of blinking red status lights made it one of the most recognizable computers ever built.