TCP Segmentation Offload

Use TCP Segmentation Offload (TSO) in VMkernel network adapters and virtual machines to improve the network performance in workloads that have severe latency requirements.

TSO on the transmission path of physical network adapters, and VMkernel and virtual machine network adapters improves the performance of ESXi hosts by reducing the overhead of the CPU for TCP/IP network operations. When TSO is enabled, the network adapter divides larger data chunks into TCP segments instead of the CPU. The VMkernel and the guest operating system can use more CPU cycles to run applications.

To benefit from the performance improvement that TSO provides, enable TSO along the data path on an ESXi host including physical network adapters, VMkernel and guest operating system. By default, TSO is enabled in the VMkernel of the ESXi host , and in the VMXNET 2 and VMXNET 3 virtual machine adapters.

For information about the location of TCP packet segmentation in the data path, see VMware Knowledge Base article Understanding TCP Segmentation Offload (TSO) and Large Receive Offload (LRO) in a VMware environment.