Hello Michael.

I did a quick and dirt test to load the HUUUUUGE file proposed by PaQ :

https://grabcad.com/library/engine-v-twin-4-valve-heads-1 (81MB more or less)

It took about 4 minutes and 40 seconds to load into Moi with my i7-4790K laptop (and Nvidia Quadro K3100M) !!!!

I've made some loading tests using both "drag and drop" and "File - Open"

During the loading Moi's was frozen and in some of the test its screen was totally black, sometimes not.
But, only when the screen was black the loading was successful.
When the screen was not black Moi's apparently discarded the model and at the and of loading Moi's viewport was totally empty.

The model is very heavy and with my Mesh Angle of 5 the rotation of the viewport was very very slow.

This is a screenshot. Please check at the Task Manager :)



This is a quick video : http://take.ms/5PDnw

Ciao!