According to one aspect of the invention, a electronic assembly is provided. The electronic assembly includes a motherboard, a first microelectronic die on a package substrate, a second microelectronic die, and a strip of flex tape interconnecting the microelectronic dies. The package substrate has a metal core with via openings, power conductors connecting a top and bottom surface of the substrate and passing through the via openings, and ground conductors interconnecting the metal core with the top and bottom surface of the package substrate. The flex tape has signal conductors which interconnect the microelectronic dies. Power is provided to the first microelectronic die via the power conductors. IO signals are sent between the microelectronic dies over the signal conductors in the flex tape.