Videomaker – Learn video production and editing, camera reviews › Forums › Technique › Editing › Help with Avidemux › I don’t know that product but
I don't know that product but what you are describing is GPU and RAM lag. It is a pretty typical result of adding any filter. Your computer is working away at trying to provide you with a live of your filter choice. If you like your filter choice, turn it off while you continue editing, then turn them back on before you render. Or add RAM and upgrade your video card and the problem goes away.