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?
Please review Low throughput for UDP workloads on Windows virtual machines (2040065) that may shed more light on this issue.