Can you confirm that it is Kbps (kilo bit per second) rather than KBps (kilo byte per second)?
Did you also check the vMotion speed from the command line using esxtop?
Thank You for paying attention to these dependencies. I have seen bad on the VmWare documentation. When started esxtop tools actually shows me a speed about 890 [MbTX/s] (Megabits per second).
So, in the Vcenter Appliance -hosts->performance->network->Usage the measurement is presented in the KiloByte unit per second and for the above measurement it was about 120000 KBps, not how I interpreted Kbps earlier.
I already understand my mistake
Thank You very much.