A structure of a multichip package and a method for fabricating the multichip package are described. The multichip package includes multiple chip stacks including chips in multiple chip layers. Each of the chip stacks includes two or more chips, each chip being inside vertical projection of at least another chip in the chip stack and disposed in a respective chip layer. Each of the chip stacks also includes horizontal conductive lines extending to perimeter regions around the chip stacks, the chips in a particular chip layer being electrically connected to horizontal conductive lines disposed in the particular chip layer. Each of the chip stacks also includes vertical conductive lines in the perimeter regions electrically connected to one or more of the horizontal conductive lines in at least two chip layers. The multichip package also includes a controller chip electrically connected to at least one chip in the chip stacks.