A system includes a high-bandwidth inter-chip network (ICN) that allows communication between neural network processing units (NPUs) in the system. For example, the ICN allows an NPU to communicate with other NPUs on the same compute node (server) and also with NPUs on other compute nodes (servers). Communication can be at the direct memory access (DMA) command level and at the finer-grained load/store instruction level. The ICN system and the programming model allows NPUs in the system to communicate without using a traditional network (e.g., Ethernet) that uses a relatively narrow and slow Peripheral Component Interconnect Express (PCIe) bus.