5K iMac and External GPU

Glockworkorange

Suspended
Original poster
Feb 10, 2015
2,511
4,176
Chicago, Illinois
I have a 2017 5K.

I know macOS has had support for external GPU's since High Sierra.

I've heard using external GPU's with an all-in-one is problematic.

What are the problems with me using an external GPU with an iMac? Is it a performance hit? Is there any way to avoid those problems?

For example, I have an LG 5K hooked to the iMac---would I hook up the external and try to just drive the LG? Would that fix the problem?

Any help would be appreciated!
 

ruslan120

macrumors 65816
Jul 12, 2009
1,117
816
I've explored this exact topic since I could not find an answer.

I've heard using external GPU's with an all-in-one is problematic.
Not really. Just in bootcamp, and the issue is not with all-in-ones. It's with bootcamp drivers if you have a Mac with a discrete GPU (driver conflicts).

What are the problems with me using an external GPU with an iMac? Is it a performance hit? Is there any way to avoid those problems?
No problems! It works great.

In terms of performance you lose a certain percentage over TB3, unavoidable. It still has benefits.

With a 2017:


With a 2019:

 
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