Slow on Mac

Hello,
SketchUp 2018 is just to slow to be operational.
(I have no problems with SketchUp Pro 8 on the same Mac).

iMac (Retina 5K, 27-inch, 2017)
MacOS 10.13.2.
4,2 GHz Intel Core i7
32 Go 2400 MHz DDR4
Radeon Pro 580 8 Go

Any ideas?
Thanks.
Ivan

Not slow on mine and it is older than yours. File size is relevant of course.

Can you provide some statistics or other information about a model that seems slow - or do all models (even a simple six-sided cube) seem slow? For example, how many edges and faces are in the model? Are there large image textures?

this suggest you never use 3D text, LayOut, the 3D Warehouse, Geo Location import, or many other things that broke along the way…

If you don’t then v8 is leaner and cleaner, and will be faster up to a point…

if your opening old files for the first time, SU will be dead slow adding all the ‘new’ criteria’ that v18 is capable of…

once updated, they should be faster…

an example of a ‘slower’ updated file may help resolve your issue…

john

Any file size, even very small.

Thanks for your input.
v8 is however instable - faster but crashes