Thanks for your information.
I found the issue in Ironcad2016. The shadow result has a fault. I attached a picture to explain it. In Ironcad2016, you can get correct shadow after switch render mode to "shaded" and switch back to "shaded with edge". Or to click "Tools | Regenerate display". After that, the render result is same as one in Ironcad2017.
Ok, now we compare the performance. Ironcad2017 is much faster. If the "Disable realistic" is checked, it will performance 3 times above faster in my machine.
As your second question, now you can't do that. This fps display is mostly used for collecting debug information. And it will slightly slow the graphics performance as well.