Realtek r8125 2.5g NIC issue
In case this type of card can not reach full 2.5g speed on Microserver gen 10 plus, select from the System Utilities screen, then System Configuration > BIOS/Platform Configuration (RBSU) > PCIe Device Configuration > Advanced PCIe Configuration, select “PCI Generation 2.0” in Maximum PCI Express Speed. If it’s set to “PCI Generation 1.0”, the maximum speed can only reach 1.5gbps when you run iperf3 to measure the NIC bandwidth.