A method and apparatus includes a plurality of processor groups each having a plurality of processor switch chips each having a plurality of processors and a processor crossbar, each processor connected to the processor crossbar; a plurality of switch groups each having a plurality of switch crossbar chips each having a plurality of switch groups each having a plurality of switch crossbar chips each having a plurality of switch crossbars each connected to a processor crossbar in each processor group, wherein no two switch crossbars in a switch group are connected to the same processor crossbar; a plurality of memory groups having a plurality of memory switch chips each having a plurality of memory controllers and a memory crossbar, each memory controller connected to the memory crossbar, each memory crossbar in each memory group connected to all of the switch crossbar in a corresponding one of the switch groups, wherein no two memory groups are connected to the same switch group.