I am here to share a solution to a problem I've encountered... I'm hoping this helps others, and perhaps someone can build on my solution...
My cMP 5,1 has 2 GPUs (Vega 56 and WX 4100) because I have 6 screens. Somebody reading this can relate, I'm sure... The Vega 56 powers the primary/larger screens, and the WX 4100 powers the smaller screens.
I also have HWAcc enabled, thanks to the activate AMD hardware acceleration thread. I posted about this issue in that thread, but I have instead moved it here because I don’t want to hijack the thread, and this info should be easy to find.
Problem: I have 2 GPUs installed. Unfortunately the lesser WX 4100 becomes the default GPU for HWAcc by macOS (decoding H264 and H264), even when the greater Vega 56 is selected for processing in FCPX. This is very annoying, because the WX 4100 can barely decode 4K video... and yes, I need more than 4 screens, hence 2 GPUs.
Solution: Below is the refined process I've found to make the Vega 56 card my default GPU for HWAcc. I've used this process over 20 times and it has worked every time. These steps must be followed exactly, otherwise the Vega 56 won't become the default. I've tried all variations and combinations, but this is the only process that makes the Vega 56 the default GPU for HWAcc:
1. shutdown
2. remove the WX 4100 (until step 7)
3. reset PRAM
4. disable System Integrity Protection (csrutil disable)
5. boot to macOS
6. enter terminal commands to set boot Open Core (using the instructions linked above)
6. shutdown
7. install the WX 4100 in a different slot than it was at step 2
8. power on - success (until the next reboot, then repeat this process)
I hope this helps someone else in future!
Does anyone have an easier method? Why does this process only work when the card is installed in a different PCI slot?
My cMP 5,1 has 2 GPUs (Vega 56 and WX 4100) because I have 6 screens. Somebody reading this can relate, I'm sure... The Vega 56 powers the primary/larger screens, and the WX 4100 powers the smaller screens.
I also have HWAcc enabled, thanks to the activate AMD hardware acceleration thread. I posted about this issue in that thread, but I have instead moved it here because I don’t want to hijack the thread, and this info should be easy to find.
Problem: I have 2 GPUs installed. Unfortunately the lesser WX 4100 becomes the default GPU for HWAcc by macOS (decoding H264 and H264), even when the greater Vega 56 is selected for processing in FCPX. This is very annoying, because the WX 4100 can barely decode 4K video... and yes, I need more than 4 screens, hence 2 GPUs.
Solution: Below is the refined process I've found to make the Vega 56 card my default GPU for HWAcc. I've used this process over 20 times and it has worked every time. These steps must be followed exactly, otherwise the Vega 56 won't become the default. I've tried all variations and combinations, but this is the only process that makes the Vega 56 the default GPU for HWAcc:
1. shutdown
2. remove the WX 4100 (until step 7)
3. reset PRAM
4. disable System Integrity Protection (csrutil disable)
5. boot to macOS
6. enter terminal commands to set boot Open Core (using the instructions linked above)
6. shutdown
7. install the WX 4100 in a different slot than it was at step 2
8. power on - success (until the next reboot, then repeat this process)
I hope this helps someone else in future!
Does anyone have an easier method? Why does this process only work when the card is installed in a different PCI slot?
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