THANKS TO ENCOURAGING GUIDES ON THIS SITE, I HAVE MANAGED TO GET MY EGPU SETUP WORKING
Macbook Pro Retina 15” Mid 2015
AMD Radeon R9 M370X 2048 MB
2.8 GHz i7, 16GB RAM
Windows 10 64bit ( bootcamp )
EVGA NVIDIA GeForce GTX 1060 6 GB GDDR5 Memory PCI Express 3 Graphics Card
EVGA 100-W1-0500-KR - 500W 80 Plus Power Supply (100-W1-0500-KR)
Molex to barrel adapter to connect PSU to GPU and enclosure
GPU powered by the PSU directly
HDMI cable to connect GPU to monitor
Thunderbolt cable to connect Thunder2 to Macbook
PSU powered on using the 'paper clip technique'
Dell U2715H 27-Inch Widescreen IPS LED Monitor
Info and guides:
Power on and connect the GPU, check that the Nvidia is showing up in the device manager
Install Nvidia drivers
Disable discrete AMD GPU in the device manager and shut down
Boot back up into Windows10 and BOOM, Windows10 should now be using the GPU.
I can reliably get the eGPU to work every time and have experienced NO CRASHES! I still play games using the AMD when I'm not at my desk, which just requires re-enabling the AMD. Sometimes switching the AMD on and off can cause the device manager to hang, but restarting Windows 10 sorts this out so I've not had any problems using the system both ways.
Doom - 1440p max settings - 60pfs ( WOW!!! )
Deus Ex Mankind Divided - 1440p max settings - 30-45 fps
Just Cause 3 - 1440p max settings - 30-45 fps
Star Wars Battlefront - 1440p max settings - 30-45 fps
Overwatch - 1440p max settings - 60fps
Getting Windows10 to select the eGPU as the primary display device:
As far as I can tell, all that is required to get the GPU to power the external display is to disable the discrete graphics chip (AMD R9 M370X) via the device manager in Windows10.
In my experience, provided the eGPU is connected, disabling the AMD R9 will automatically cause the OS to switch to the eGPU. Although a couple of times when I've done this without restarting, the AMD has switched itself back on!
Provided the eGPU is connected and powered on, and the AMD is disabled, booting into Windows 10 will automatically select the eGPU and you're away!