Abstract: A hybrid computing system comprising: a network fabric; at least one Root Complex board (RCB) and at least one Endpoint Board (EB). Each Root Complex board (RCB) comprises a first processor; a PCIe root complex connected to the first processor; and a first PCIe network switch directly connected to the PCIe root complex. Each Endpoint Board (EB) comprises a second processor; a PCIe interface connected to the second processor; and a second PCIe network switch connected to the PCIe interface. The PCIe network switches of each board (RCB, EB) are connected to the network fabric wherein each Root Complex board (RCB) and each Endpoint Board (EB) are configured for simultaneous use within the hybrid computing system.