I was trying to think of the best way to make a huge pile of irregularly shaped objects, like action figures. I also want to animate a stream of objects falling on to the pile.
The problem is that there is obviously a lot of geometry in an action figure, and even if I edit them so they are as low-poly as possible, I want there to be enough detail that you can see arms and legs poking out of the pile. This results in impossibly slow playback in the viewport, and it would be great to see the results in the viewport before rendering.
I tried cloning a bunch of them on to a cone and creating some "filler" objects underneath to give the impression that there are a lot of action figures in the pile, but it's still super slow.
One thing you can do with dynamics is build a low poly collision shape and assign it to a high poly object. You assign it by going to the dynamics collision tab, collision shape, and selecting "Another Object". Then you drag your low poly object into the link box.
In order to reduce memory requirements you can put your objects in a cloner and check the "render instances" box.