A computer subsystem and a computer system, where the computer subsystem includes L composite nodes (CNs), each CN includes M basic nodes, each basic node includes N central processing units (CPUs) and one node controller (NC). Any two CPUs in each basic node are interconnected. Each CPU in each basic node is connected to the NC in the basic node. The NC in each basic node has a routing function. Any two NCs in the M basic nodes are interconnected. A connection between the L CNs formed through connections between NCs enables communication between any two NCs to be no more than three hops. Hence, the computer subsystem and the computer system can reduce the kinds and the number of interconnection chips, and simplify an interconnection structure of a system, thereby improving reliability of the system.