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rondocap

macrumors regular
Original poster
Jun 18, 2011
130
3
I have a 2019 Mac Pro, with the W580x installed. I added a Vega 64 GPU, and am using an LG 5k Monitor via Thunderbolt.

The 580x defaults to the display gpu, is there any way I can change that to the Vega 64? The monitor has thunderbolt to the back of the Mac Pro. I know if I plug in an HDMI cable to the GPU, it defaults to the display GPU, but anyway I can do that and still use the thunderbolt connection?

Also, does it make a difference for which GPU is the display GPU when using FCPX or Resolve which take advantage of multi gpu? Would it be faster if the Vega 64 is the primary display GPU or won't matter?
 

mattspace

macrumors 68000
Jun 5, 2013
1,608
1,257
Australia
I have a 2019 Mac Pro, with the W580x installed. I added a Vega 64 GPU, and am using an LG 5k Monitor via Thunderbolt.

The 580x defaults to the display gpu, is there any way I can change that to the Vega 64? The monitor has thunderbolt to the back of the Mac Pro. I know if I plug in an HDMI cable to the GPU, it defaults to the display GPU, but anyway I can do that and still use the thunderbolt connection?

Also, does it make a difference for which GPU is the display GPU when using FCPX or Resolve which take advantage of multi gpu? Would it be faster if the Vega 64 is the primary display GPU or won't matter?

AFAIK:

So your monitor is thunderbolt, which requires a thunderbolt video-out. The only GPUs with thunderbolt video out (either from the GPU's ports, or via the built-in Thunderbolt ports) are MPX GPUs. Your PCI-only Vega 64 can only do display duty, when a monitor is plugged directly into it, and that monitor would have to be DP/HDMI.

The best you're going to get is the Vega-64 as a compute accelerator.
 
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flowrider

macrumors 603
Nov 23, 2012
6,457
2,472
^^^^Not really. I am using a TB LG monitor. I have run it with a bidirectional cable:


And with this cable:


Lou
 
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