System with external expansion GPU (graphics processing unit) cards

The invention relates to an expansion technologies for graphics processing units (GPU), in particular to a system with external expansion GPU cards. The system is characterized in that servers are separated from the GPU cards, and the GPU cards are placed on special GPU nodes. The servers are connected with the GPU nodes by special connecting cards and Cables. The system has the advantages that the problem of constraints of GPU card spaces, power supply and heat dissipation can be solved owing to the external GPU cards; the two corresponding GPU cards can be expanded on a PCIE (peripheral component interface express) x16 slot in a mainboard of each server via a PCIE Switch, so that the quantity of the expansion cards can be increased; the GPU nodes can be intelligently managed by management modules in a case, and heat generated by the GPU nodes can be dissipated by the aid of the management modules in the case.