When i connect via xrdp 0.9.1-9+deb9u3 -> xorg from windows RDP client to Debian 9.5 i have this 
message on Desktop
Running in software rendering mode
Cinnamon is currently running without video hardware acceleration and
as a result, you may observe much higher than normal CPU usage.There could be a problem with your drivers or some other issue. For
the best experience, it is recommended that you only use this mode for
troubleshooting purposes.
How avoid this problem?
Best Answer
There is an experimental GPU-enabled version of xorgxrdp (part of xrdp). Details are in https://github.com/neutrinolabs/xrdp/issues/1029, code itself https://github.com/jsorg71/xorgxrdp/tree/glamor
Look and feel looks way better in my setup, your mileage and support of graphic adapters might vary. Be ready for high CPU usage by xrdp when something is actively updating on the screen, ie watching video.