I have 2 Esxi 6.0 servers. There is on Debian Linux virtual machine in each of these servers. The Linux virtual machines are connected by a 10Giabit X540 AT2 network adapters (back to back) . A single connection UDP throughput does not go beyond 850Mbps. However with multiple UDP connections can go beyond 850Mbps (with 3 connection it is 3 * 8950 Mbps). The maximum throughput achieved is around 4Gbps (a single tcp or with mulitple UDP connections). A standard switch is created in each Esxi Serverr for the network adapter.
Whey is single UDP connection throughput limited to 850Mbps where as single TCP connection can reach 4Gbps?