If you are experiencing slow or choppy gameplay whilst playing on CnCNet, there are a few steps you can take to troubleshoot the problem.
Install the CnCNet client (Skip to step 3 if already installed)
This will look for your existing game directory.
Once installed run CnCNetYRLauncher.exe or the shortcut supplied.
Select "Display" and under the render options, select a new renderer. Commonly, Automatic works best.
Click Save, and launch Skirmish.
Play a game with the AI. If the gameplay is fast then this renderer will likely be the best for you.
If it hasn't worked, repeat from step 5 until you find a renderer that works best with your system.
Now you can close CnCNet, and launch the Origin game. These should now work too.
Failing the above, ensure your video drivers are up-to-date. You are running a suitable resolution the game can handle.