tnw2933

I received my 10 core iMac Pro on December 26th 2017.  I noticed immediately that 95% of the time when I woke my iMac Pro from sleep all the external USB drives were ejected.  This occurred for various external USB3 hard drives from different manufacturers as well as with a Sandisk Extreme 64 GB USB3 flash drive and a 16 GB USB2 Kingston flash drive.  I also discovered that I could not boot into Windows 10 if any external hard drives were connected and that I could not use the Option key> Storage Manager to boot into Windows 10 regardless of whether USB drives were connected or not.  I filed a formal case with Apple Support on January 2, 2018 and I have since been in touch with a total of five Apple Support contacts regarding these two issues -- three of whom are Senior Advisors.  To date, the problem still exists, and I still have an open case with Apple.  I have been using the iMac Pro with Thunderbolt 3 and Thunderbolt 2 external hard drives without any problems as long as I do not attach USB drives to the iMac Pro and put it to sleep.  

I have also done extensive editing in FCP 10.4 (latest version) with my iMac Pro.  While some things are indeed faster than my fully maxed out Late 2013 Mac Pro cylinder, I have found that for many common tasks the CPU's and presumably the graphics card are not being used to full efficiency by the iMac Pro in FCP 10.4.  Overall, I have been disappointed with my purchase of this nearly $9,000 computer and especially with the fact that after more than two weeks of working with Apple Senior Advisors (who in turn are passing along information to an engineering team) I am no more able to effectively utilize USB external hard drives with my iMac Pro than I was the day I received it form Apple. 

Tom