I’m pretty sure that the Checksum Offload causes a bunch of network slow downs – especially in a virtual environment.
Whenever a customer says that it takes a good few seconds to open i.e. a Word document, placed on a share, I always disable Checksum Offload wherever possible on the NIC, inside the VM. This has always been the main reason for the slow downs. I’m not sure why exactly, but it seems that disabling this feature solves the problem!
Any comments are welcome!