Abstract: The CPU+GPU architecture design is widely used in the data collection and processing requirements of AI servers for big data, cloud computing, artificial intelligence and other fields. The commonly used CPU+GPU PCIe topologies include Balance Mode, Common Mode, and Cascade Mode. In combination with practical requirements, the applicability of various topologies should be studied for complex and diverse application scenarios. Firstly, the architecture of the three topologies is briefly introduced, and then the experiment is designed. The applicability of the three topologies is analyzed through the performance of the point-to-point bandwidth and delay, deep learning and double precision floating point operation. At last, the guidance for the PCIe topology selection of AI server is provided in practical application.

Key words: AI server, PCIe topology, application scenario