bda_jaime

Much appreciated, that's reassuring. Mine is 4.0GHz quad-core Intel Core i7, Turbo Boost up to 4.2GHz, 16GB 1867MHz DDR3 SDRAM - two 8GB, 1TB Fusion Drive, AMD Radeon R9 M390 with 2GB video memory, so similar. I'll see if any other responses come in and then will install High Sierra. Worse case I can always roll back to Sierra.

I was going to update the OS on my iMac with Fusion drive but read on a forum that updating a Mac to High Sierra OS makes the processing time for rendering 3D objects or high end architectural renderings increase substantially even with all application software and plugins updated to the latest versions. Does anyone have any experience or comment on this?