2015 Macbook Pro 15inch iGPU

[han310]

Hi. Sorry if this has been answered somewhere but it's still a little unclear to me... 

Is it possible to get an eGPU running on the 2015 rMBP 15" without the dedicated AMD card in BootCamp? 

 

I ask this because I had everything working with my old 2014 rMBP 13" in Win10. Except I can't seem to get it working on this new 15".. 

and I've seen people who've gotten it working here with a 2015 13" and 2015 15" with dGPU, so it's probably something I'm doing wrong? 

 

edit.

whoops think i posted this in the wrong place. 

Edited June 9, 2016 by han310

[dmilin]

I have an Akitio setup with an nVidia GTX 970 with a 2015 15" without the dedicated GPU and mine works fine with my setup on Windows 8.1. It doesn't always boot correctly though, and usually takes at least 5 minutes of boot attempts to get it to start up correctly.

[han310]

Do you mind sharing your boot process? 

[dmilin]

Honestly, the boot process doesn't seem to matter. I've tried to find a pattern that works, or a pattern that doesn't work, but it seems random. The one thing I have found that does cause an issue, is the thunderbolt port in use. For example, if I install the drivers with my thunderbolt cord in the port closest to the power cord, and the other end in the higher port on the Akitio enclosure, I'll get a boot issue if I have it connected any other way. The specific ports in use don't matter, just that they are the same as driver installation. My process is:

 

1. I will assume no drivers are installed yet. I start with the computer off and the eGPU off. I plug the thunderbolt cord into the mac (any port, but remember which port) and the other end into the eGPU.

 

2. I power up the eGPU and then turn on the mac maybe 2 seconds later. I select the BootCamp disk and it boots up (sometimes). Device manager should recognize it, but you can't use it. If it fails to boot by restarting, endless loading wheel, or says something about loading device helper (don't remember exact wording), you need to turn off the eGPU by switching off the PSU, and turn off your Mac by holding the power button. Just keep trying this until it boots.

 

3. Once it finally boots, install the newest nVidia driver for the GTX 970 in Windows 8.1 in 64 bit mode. Hopefully this should go fine. If the installer says something about not recognizing a compatible GPU, go back to step 1 and try again. This sometimes takes patience to get to work.

 

4. After it finally installs, reboot your computer and use the same boot process I described in steps 1-2.

 

This works for me. Hopefully it will work for you. It's worth noting that I installed Windows through the standard BootCamp install process. I didn't do that weird UEFI install or whatever it's called.

[han310]

I've been around some other threads around here and one came up with this just now. I've been able to boot up almost every time. 

Drivers are already installed. 

eGPU is already powered on but not connected. Macbook is powered off. 

Boot into windows, but insert the thunderbolt cable into mac right after the windows logo appears. 

This is in win8.1. 

I'm gonna try it in win10 maybe tomorrow. 

[dmilin]

Haven't tried that yet. I just installed rEFInd and tried turning on the eGPU while at that menu after enabling Mac EFI mode in the settings. Out of the 2 times I've tried to boot so far, it's worked successfully both times which is a better success rate than I usually have. By the way, from what I've seen on this forum, you will likely have problems trying to run using your internal display in Optimus if you use Windows 10. Just a heads up.