I have two FX busses, with reverb and a chorus. If I have them active I get bad performance and pops and dropouts.
Also noticed moving the mixer window around increases power consumption high "very high" in the task manager.
I am on windows 10 , Vegas Pro 17 using a Korg Kronos as input device and a USB Yeti Microphone as headphone monitor.
In FLstudio the performance is very good so I assume it is something with Vegas!