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