is there a maximum speed limit on a vmxnet3 adapter?

hi all,

I was doing some testing on the throughput of our vSwitches and I'm only getting 1Gbits/s throughput from a VM on the same vSwitch.

Both clients are using vmxnet3 network adapters, is there some configuration I need to change as 1Gbits/s seems to be a glass ceiling?

thanks in advance.