Better previewing if the layer is trimmed instead of greyed out?
I'm using a macbook air (Processor: 1.6 GHz DDR3, Memory 8GB 1600 MHz DDR3, Graphics: Intel HD Graphics 6000 1536 MG) and running AE cc.
Though I am a beginner, I can tell that this computer is not the best for intensive AE. The previewing is very slow (always in quarter resolution). So, I am trying everything to make things easy for my computer.
For example, should I trim the precomp (Layer Name: Big Robot) instead of making it short by "greying it out"?

Also, if an image/shape etc is not visible and you are not using it you should trim it or delete it since AE will try to render it anyways?
I am fairly certain that you should but I just want to make sure.
Thank you!