MP 1,1-5,1 Advice on Mojave upgrade

[1stCameLC]

I have a MacPro5,1 still in High Sierra that I'd like to upgrade to Mojave.

Current PCI-e cards:
Slot 1: NVIDIA GTX 1080 Ti
Slot 2: empty
Slot 3: Kingston NVMe
Slot 4: NVIDIA GT 120

I'm thinking of getting a RX 560, putting it to slot 1 during the upgrade and then moving it to slot 2 or 3 after the upgrade when the 1080 Ti goes back to slot 1. I would use the RX 560 on the macOS side and 1080 Ti on the Windows side only. Will there be potential problems with this?

My boot drive (plain SSD, not the NVMe) is partitioned in half for macOS and Windows like this:

/dev/disk2 (internal, physical): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *1.0 TB disk2 1: EFI EFI 209.7 MB disk2s1 2: Apple_APFS Container disk3 500.1 GB disk2s2 3: Microsoft Basic Data WIN10 499.8 GB disk2s3 /dev/disk3 (synthesized): #: TYPE NAME SIZE IDENTIFIER 0: APFS Container Scheme - +500.1 GB disk3 Physical Store disk2s2 1: APFS Volume HighSierra 258.7 GB disk3s1 2: APFS Volume Preboot 21.9 MB disk3s2 3: APFS Volume Recovery 512.1 MB disk3s3 4: APFS Volume VM 20.5 KB disk3s4

Will this cause any problems with the Mojave installation?

 

[h9826790]

I have a MacPro5,1 still in High Sierra that I'd like to upgrade to Mojave.

Current PCI-e cards:
Slot 1: NVIDIA GTX 1080 Ti
Slot 2: empty
Slot 3: Kingston NVMe
Slot 4: NVIDIA GT 120

I'm thinking of getting a RX 560, putting it to slot 1 during the upgrade and then moving it to slot 2 or 3 after the upgrade when the 1080 Ti goes back to slot 1. I would use the RX 560 on the macOS side and 1080 Ti on the Windows side only. Will there be potential problems with this?

My boot drive (plain SSD, not the NVMe) is partitioned in half for macOS and Windows like this:

/dev/disk2 (internal, physical): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *1.0 TB disk2 1: EFI EFI 209.7 MB disk2s1 2: Apple_APFS Container disk3 500.1 GB disk2s2 3: Microsoft Basic Data WIN10 499.8 GB disk2s3 /dev/disk3 (synthesized): #: TYPE NAME SIZE IDENTIFIER 0: APFS Container Scheme - +500.1 GB disk3 Physical Store disk2s2 1: APFS Volume HighSierra 258.7 GB disk3s1 2: APFS Volume Preboot 21.9 MB disk3s2 3: APFS Volume Recovery 512.1 MB disk3s3 4: APFS Volume VM 20.5 KB disk3s4

Will this cause any problems with the Mojave installation?

I don't know why you want to do this. But if you don't need GPU power in macOS anyway, you don't even need the RX560.

You can install Mojave with only the 1080Ti installed. Of course, you won't able to see anything after Mojave is installed. But then you can install the GT120, and use the GT120 in Mojave.

In this case, you can run both Mojave and Windows with your current hardware.

 

[1stCameLC]

I don't know why you want to do this. But if you don't need GPU power in macOS anyway, you don't even need the RX560.

You can install Mojave with only the 1080Ti installed. Of course, you won't able to see anything after Mojave is installed. But then you can install the GT120, and use the GT120 in Mojave.

In this case, you can run both Mojave and Windows with your current hardware.

MacOS is for day to day use and Windows for occasional gaming. I don’t need the GPU power on the Mac side.

I was under the impression that 1080 Ti can’t be used for the upgrade since it isn’t supported in Mojave, but you’re saying it works for upgrading just not after that?

The last time plugged in the GT 120 it showed a distorted picture so it might be failing and I need another basic GPU anyway. Would RX 560 work in this combo? I know it’s a double slot card but should probably fit with the NVMe and looks like it works with just the PCIe slot power.

 

[h9826790]

MacOS is for day to day use and Windows for occasional gaming. I don’t need the GPU power on the Mac side.

I was under the impression that 1080 Ti can’t be used for the upgrade since it isn’t supported in Mojave, but you’re saying it works for upgrading just not after that?

The last time plugged in the GT 120 it showed a distorted picture so it might be failing and I need another basic GPU anyway. Would RX 560 work in this combo? I know it’s a double slot card but should probably fit with the NVMe and looks like it works with just the PCIe slot power.

You need a card that's supported in High Sierra to install Mojave. You run the Mojave installer in High Sierra, not Mojave. I tested that since Mojave beta.

It should work. However, a bit more complicated in Windows.

In Mojave, since the 1080Ti is not supported, and no driver at all. Therefore, it won't affect the system.

However, in Windows, you have to disable the RX560. e.g. change that to use the "Microsoft basic display adaptor" (or something like that), completely cleanup the AMD driver, then install the Nvidia driver for the 1080Ti.

Having both AMD and Nvidia driver installed in Windows can lead to disaster.

If possible, sell the 1080Ti, buy a Vega64 or Radeon VII, then run both Mojave and Windows with this single GPU should be way easier.

If you just occasionally gaming in Windows. This setup also make more sense.

Keeping a 1080Ti in the cMP without proper driver to initialise it most of the time. Doesn't sounds like a good idea to me. I am not 100% sure about if the following applicable to the 1080Ti, but without driver, the GPU may stay at high clock speed all the time, unable to go into low power mode. So, even though the demand is low, but the core temperature can still quite high. And you keep burning its life for absolutely nothing (not even able to provide basic display).

 

[1stCameLC]

Keeping a 1080Ti in the cMP without proper driver to initialise it most of the time. Doesn't sounds like a good idea to me. I am not 100% sure about if the following applicable to the 1080Ti, but without driver, the GPU may stay at high clock speed all the time, unable to go into low power mode. So, even though the demand is low, but the core temperature can still quite high. And you keep burning its life for absolutely nothing (not even able to provide basic display).

Indeed that doesn't sound good. Switching to Vega 56/64 or Radeon VII might be the move if I can find one decently priced. Used ones on eBay seem to be available but can cost as much as a new one but new ones don't seem to anywhere anymore.