late-2013 Mac Pro D500s + [email protected] (Mantiz Venus via TB3-to-TB2 adapter) + macOS10.12.6 [theitsage]
I gave multiple monitor eGPU setup a try tonight to assist @Hypernurd with his nMP eGPU implementation. All 3 displays were able to run off a GTX 1070 + Venus Mantiz. The main monitor has dual input sources (one from the nMP HDMI and the other from eGPU DisplayPort). HDMI connection is to see the Boot Screen/Selector when needed. Otherwise the monitor is set in DisplayPort input for the eGPU acceleration.
The other two monitors are straight forward. There's no special tricks. I connected the Thunderbolt 2 cable to Port 5 - Thunderbolt Bus 0 as shown in the picture below. Thunderbolt 2 port 1, 2, 3, 4 cause hang at boot and require boot delay. I used goalque's automate-eGPU script. I restarted multiple times as well as cold boot with all monitors powered on and connected, not a hiccup.
Thanks for setting up this implementation guide page. Good to see you've had some success with the multiple monitor set-up. I, alas, am not. Here's where I'm at;
• My main display (4k Iiyama) is on HDMI to the internal nMP port
• Venus connected to Port 5 (TB0)
• Single 4k Iiyama connected via DP to 1080Ti.
Outcome - HDMI screen works, DP screen does not.
So, I de-installed everything (automate-eGPU.sh and Nvidia drivers). Disconnected all external peripherals (USB, ethernet). Shut down. Reboot in to Recovery. Checked SIP disabled. Shutdown, connected eGPU, reboot, re-run automate-eGPU.sh. Reboot.
Nothing on HDMI now. Shutdown, disconnected eGPU, reboot. Re-ran automate-eGPU.sh with -a argument. Reboot.
HDMI now works but DP display still doesn't. Hmm, I thought what's up? Shut down but connected 2nd display via HDMI to eGPU. Rebooted.
Success. I now had directly attached HDMI working and eGPU HDMI working. Great!
(Observation : The resolution of the internal HDMI had increased from my previous setting when it was working stand-alone. No biggy).
So, decided to go one step further and connect 3rd display the same way. Shut down, changed connections from DP to HDMI on eGPU. Rebooted. Nothing. Internal HDMI screen energises but no boot loader. Both eGPU displays fail to energise.
OK, I thought. Shut down and disconnect 3rd display. Rebooted. Nothing. Internal energises but no boot loader and 2nd display still dead.
Tried Port 6. Same issue. Disconnected eGPU. Rebooted. Now internal HDMI working.
So, whilst I was able to get two displays functional for a short time over HDMI only, three displays appear to be impossible and stability is clearly an issue.
Got me thinking. What's different between yours and mine. The only thing I can put my finger on is;
• CPU - you're 6 core, I'm 4 core
• Integrated GPU - you're D500's I'm D300's
• RAM - you're 32GB, I'm 16GB.
Clearly there is something in the system differences, most likely vRAM on the D300's that is causing the issue. Incidentally, I can run all three monitors via TB2 to Display port or HDMI no problem. So the system can run 3x displays....just not via NVidia's drivers via eGPU it would appear. At least, not for me.
Could the DP version setting on the Iiyama monitors have anything to do with this? I can select DP v1.1 or v1.2. I assumed because the card supports v1.2 I should have the displays set to this setting. I'm reaching I know, but thought I'd mention it.
@hypernurd Have you tried only one monitor to receive HDMI from the nMP and DisplayPort from the eGPU? Use the OSD to switch from one input to another. Try switching the DP settings on the monitor as well and see what happens.
I don't think the specs of our nMPs matter. The bigger difference is the display resolutions. None of my tested monitors was 4K. Do you have a lower resolution monitor to test through eGPU?
No, I haven't tried that. Good idea.
I don't have any lower res units here. I will try hard setting the display res to 1080p and see if this helps. I'll also try the DP version.
It also matters whether the 4K monitor is SST or MST. Not all monitors are compatible.
Thanks for the heads up regards SST/MST. Regrettably, I have not been able to determine what the Iiyama Gold-Master GB28888UHSU is from details I've found but as I've been away for a few days since your post I've not had a lot of opportunity. I will probably have to resort to contacting Iiyama support for confirmation.