Tree leaves disappearing during view port render

[timAugustine]

I was fortunate enough to update my PC to a newer graphics card and the issue completely disappeared. So I guess this issue got resolved, in a way?

Thank you for the suggestions on how to troubleshoot this, if this happens again.

[timAugustine]

I think I figured out the issue. The tree mesh was duplicated three times. I guess I should have noticed earlier that the read out said 29 M polygons instead of 9 million polygon. This happened with two different trees that I'd used. One made by me in speedtree and other downloaded from maxtree. Did I actually duplicate the mesh on two different trees?

At least I now know what to look out for.