We'll, I'm kind of new to After Effects so please forgive me if I am doing something wrong.
I am working with a 10 second clip that is a basic 3d background and some plain text with light animation. When I turn up the ray tracing 3d option to 9 to render the final product, it's painfully slow. I'm talking it's giving me a time estimate of 21 hours, for a 10 second clip! Is this normal? Am I doing something wrong? I'm working on the high end late 2013 27" iMac. I would expect a lot better performance.
May be normal, especially if your GPU is not supported. Hard to tell without system and project details. Without any more details you might have just as well asked, "How much water will it take to fill it up?" Then I ask, "Fill what up?" Then you say . . .
Why are you cranking the quality all the way up to 9? Did you determine with a RAM preview that this is the lowest acceptable setting? That is a very high amount. I've never seen a scene that needs higher than 6. Render time goes up by the square of that setting.