Neodomus

No, simply install the original script without changing anything. 

 

Then restart the iMac.

If everything worked out, you should have an output on your external monitor via the egpu, and the iMac should have switched to the "weird" resolution.

NOW sent it to sleep mode, wait a few seconds and wake it up. The iMac should switch back to "normal" mode.

 

The other solution you mentioned can be used in case you only want to use the egpu in apps to render stuff, but not if you want to display something on the external monitor, as far as I understood.

 

goalque explained both options in the thread I linked, but you have to scroll down a bit to find the "sent-it-to-sleep" method.

 

Concerning your Octane issue, I have no clue.

Hi Slang,

 

I had the same problem. I found a solution in this thread. Had to put my iMac 5k to sleep, waited a couple of seconds, woke it up again. The iMac display switched back to "normal". Had to adjust the resolution, though.