CPUs that generate PCIe auxiliary signals and changing clock signals nevertheless communicate with each other using PCIe owing to PCIe switch assemblies that are disposed in the communication paths to isolate and terminate the auxiliary signals from reaching other CPUs and to isolate changing clock signals, communicating with each other using a fixed clock derived from one of the changing clock signals. Also, the CPUs directly access the memories of CPUs to which they wish to write data so that data is directly written from one CPU memory to another without store-and-forward operations being needed in the network.