A 3D device including: a first level including first transistors and a first interconnect; a second level including second transistors, the second level overlaying the first level; and at least eight electronic circuit units (ECUs), where each of the at least eight ECUs includes a first circuit, the first circuit including a portion of the first transistors, where each of the at least eight ECUs includes a second circuit, the second circuit including a portion of the second transistors, where each of the at least eight ECUs includes a first vertical bus, where the first vertical bus includes greater than eight pillars and less than three hundred pillars, where the first vertical bus provides electrical connections between the first circuit and the second circuit, where the second level is bonded to the first level, and where the bonded includes oxide to oxide bonding regions and metal to metal bonding regions.