eGPU and boot camp issue

HalFried

macrumors newbie
Original poster
May 14, 2015
9
3
Just set up my new macmi (32g ram) yesterday. Also installed WIN10 with bootcamp. No issues. Also added eGPU (Razer Core X)with Radeon RX Vega 64 and that is working fine with Mojave. Problem is trying to setup WIN10. All I get is a black screen and the monitor power light keeps flashing as if it is not receiving a signal.

When starting up I do get the the option to select the Windows partition by holding down the option key but nothing happens after I select it. Note that this is with the eGPU unplugged.

Hope someone here can give me info on how they were able to get this to work. I did watch installation video over on 9to5 Mac but they didin't go into detailed instructions on installing drivers and card for Windows on bootcamp.
 

rmdeluca

macrumors 6502
Oct 30, 2018
250
392
I'm a bit confused by this:

Also installed WIN10 with bootcamp. No issues.
then this:

When starting up I do get the the option to select the Windows partition by holding down the option key but nothing happens after I select it. Note that this is with the eGPU unplugged.
I have to ask first: you do have the monitor plugged into the eGPU's video output, right? Not the Mini? Assuming so:

Windows did originally boot correctly before you added the eGPU, right?

If not, that should be your first step. Reinstall Windows without the eGPU connected. Once that's working:

Then connect the eGPU live while Windows is already booted and sitting at your desktop, with monitor still plugged directly into the Mini. Let Windows install whatever default drivers it has.

Then plug your monitor into the eGPU's video outputs and make sure you get a picture. Reboot and make sure it comes back up.

If at that point you get a black screen while booting into Windows, try connecting a second monitor directly to the Mini (or if your monitor has multiple inputs, use one of those) and see if you're still able to get a picture from the Mini's iGPU. That will at least tell you that Windows isn't hard locking or failing to boot.

Once everything is working, then you can try installing AMD's latest drivers.

In my experience an unexpected reboot or two is often necessary when first coaxing Windows from the iGPU to eGPU.
 
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IngerMan

macrumors 65816
Feb 21, 2011
1,343
310
Michigan
I can agree with rmdeluca.

I recently installed Bootcamp for about the 4th time. I have an Asus Pro station and Vega 56 card.

What I learned is on the initial install of BootCamp. Do not have the eGPU on and use the Mini HDMI for complete windows installation or another Mini port adapter.

After Installation is complete and I did all my Windows updates. I shut down and turned back on the eGPU but I found I had to remove the HDMI cable from the Mini before powering back up to get the eGPU to be recognized. I might even had to do another force boot.
 
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HalFried

macrumors newbie
Original poster
May 14, 2015
9
3
I'm a bit confused by this:
.....
In my experience an unexpected reboot or two is often necessary when first coaxing Windows from the iGPU to eGPU.
Thanks for the tips. Sorry that I didn't make it clear that all was working well with the bootcamp installation up to installing the eGPU.

I have it working now. Am able to boot into windows or mac and no issues with either one. However, when I start the mac mini and hold the option key the screen stays dark. I have to guess when the screen would normally show up where you to select which OS to go into. When holding down the Option key it will default to Win10, so I normally wait about 10 to 15 seconds and press the Enter key. That works pretty well for getting into Win10. If I simply want to go to Mojave, I don't press the Option key and it will boot into Mojave.

Also, think you are right that it can take a couple of reboots before things start working correctly. Leastways, that's how it worked out for me.
 

rmdeluca

macrumors 6502
Oct 30, 2018
250
392
However, when I start the mac mini and hold the option key the screen stays dark.
Ah, yeah this is because the video card doesn't have the right firmware for the Mac to be able to display its built-in boot menu. I personally just use System Preferences to reboot into Windows, and Apple's Boot Camp utility to boot back into macOS. Others use a second connection to their monitor (directly from the Mini) and switch to that connection when they need to see the boot menu or enter FileVault/startup passwords.
 

vagos1103gr

macrumors regular
Jul 25, 2013
208
13
or you can
Ah, yeah this is because the video card doesn't have the right firmware for the Mac to be able to display its built-in boot menu. I personally just use System Preferences to reboot into Windows, and Apple's Boot Camp utility to boot back into macOS. Others use a second connection to their monitor (directly from the Mini) and switch to that connection when they need to see the boot menu or enter FileVault/startup passwords.
or use a small app like bootchamp. It stays on the startup and make it easy to reboot from win to Mac, but unfortunately stopped after Mojave to work inverse.
 

HalFried

macrumors newbie
Original poster
May 14, 2015
9
3
Ah, yeah this is because the video card doesn't have the right firmware for the Mac to be able to display its built-in boot menu. I personally just use System Preferences to reboot into Windows, and Apple's Boot Camp utility to boot back into macOS. Others use a second connection to their monitor (directly from the Mini) and switch to that connection when they need to see the boot menu or enter FileVault/startup passwords.
Wow! Thanks for that great tip. I didn't realize there was a setting like that in System Preferences. Works great.

My background in computers is mainly in the PC camp. Am still learning the MAC OS system.
 
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smbu2000

macrumors 6502
Oct 19, 2014
261
111
You already have Win10 installed and your egpu installed?
Does your monitor have 2 display inputs free?

What I usually do on mine is I leave the mac mini plugged in directly into Displayport #1 on my monitor and I have my eGPU (Razer Core X + 1080Ti) plugged into Displayport #2 on my monitor. When I start up the computer (holding the option key) it defaults to the output display on the mac mini (Displayport #1) and I can see both my Mojave install and Win10 install. Then when I click on Win10, it starts up and the mac mini display is disabled and it switches over to the display output via the eGPU(Displayport #2). After that I can use Win10 just fine via the eGPU. Checking GPU-Z also shows that my 1080Ti is the default display device.

This also worked fine with my previous card that I used in the eGPU box, a Vega 64 card. It uses two display inputs on your monitor, but I've had no problems since I started doing it this way.