Refer to Chapter 3, Networking Performance Design, where the Selecting the correct virtual network adapter recipe talks about the trade-off factors in choosing the correct adapter.

For the best performance, use the VMXNET3 network adapter for operating systems in which it is supported. The VM must use a virtual hardware of version 7 or later, and VMware Tools must be installed in the guest operating system.

For the best networking performance, use network adapters that support hardware features, such as TCP checksum offload, TCP segmentation offload, and jumbo frames.

Ensure that the network adapters have the proper speed and duplex settings. Typically, for 10/100 NICs, set the speed and duplex. Make sure that the duplex is set to full duplex. For NICS, Gigabit Ethernet, or higher, set the speed and duplex to the auto-negotiate.

You can also choose E1000, which is an emulated version of the Intel 82545 EM Gigabit Ethernet NIC. A driver for this NIC is not included with all guest operating systems. Typically, Linux versions 2.4.19 and later, Windows XP Professional x64 Edition and later, and Windows Server 2003 (32-bit) and later include the E1000 driver. E1000 does not support jumbo frames prior to ESXi/ESX 4.1.