Transfer rate between ESXi host using "Veem backup and FastSCP"

Dear all,

I have two ESXi host connected with different 1G-Eth ports on an HP switch

now I'm trying to transfer data between the two hosts using "Veem backup and FastSCP" tool

a transfer rate of 1MB/s is normal? do you know a way to enhance network performances?

note that no collisions or mismatch discovered on the switch port

thanks in advance