I’ve got the same problem – I just did a completely fresh install of Xubntu 14.01, after failing to fix it on 13.10
What is the nx process with high CPU usage?
Does the CPU usage remain high when there are no visible updates in the session?
Yes, and input is also unusably slow
NoMachine product and version on local and remote machine (free version, Workstation, etc).
Client: 4.1.29, OSX
Whether the problem arises connecting to a physical or a virtual display.
Physical. As far as I can tell, the free version doesn’t do virtual displays?