About UDP Performance

NIC: ConnectX5 MCX516A-CCAT
NIC FW: v16.35.1012
NIC Driver: v5.7-1.0.2
OS: Ubuntu 20.04 LTS

  1. We use Dual CPU (Intel Xeon Silver 4314). Two Connect X-5s were installed in one PC to configure 4 channels.
    We want to achieve performance of around 3.5GByte/s per channel by using only a single thread per channel.
    However, when measuring the performance of 4 channels by writing UDP samples using recvfrom() and sendto(), only about 2Gbyte/s per channel comes out. (Send byte and receive byte are set to 8k)
    Is there anything I can look into for better performance?

  2. In the sendto() and recvfrom() functions, there is a problem that communication is cut off when the size is set higher than 8k. (example: 16k, 32k, 62k, …)
    Is there a setting that I have to set up to make the size bigger than 8k?