2018 15" MacBook Pro (RP560X) [8th,6C,H] + RX 5700 XT @ 32Gbps-TB3 (Sonnet Break...
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2018 15" MacBook Pro (RP560X) [8th,6C,H] + RX 5700 XT @ 32Gbps-TB3 (Sonnet Breakaway 550) + macOS 10.15.5 & Win10  


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Joined: 2 years ago

Hey everyone, here's what I hope is a simple working build guide for a 2018 15" MBP for a Catalina/Bootcamp eGPU setup.


System specs 

- 2018 15" MacBook Pro , 2.6ghz i7-8850 6-core CPU, 32GB Ram, 1TB SSD

- 24" LG 4k monitor via DisplayPort 1.2

eGPU hardware (eGPU enclosure, video card, any third-party  TB3 cable , any custom mods)

- Sonnet Breakaway 550

- MSI Evoke RX5700XT 

- Belkin 2 Meter active TB3 cable

Installation steps (what did you do to get it all going?)

- This is plug and play on MacOS Catalina, which was a primary requirement driving me toward an AMD-based eGPU solution over Nvidia, since the eGPU is the basis of a de-cluttering workstation that I built at my desk (nothing fancy, just ran some wires behind the desk, etc, point being its not mobile) and my workflow is MacOS based.

- For Bootcamp, this ended up being surprisingly simple but it required a little fussing (and a little more money on software). In short, I used the pci.sys replacement trick to get this working first on Windows 10 build 1909 and now on Windows 10 build 2004. Here's how I did it:

1) Install Windows Bootcamp the normal way from MacOS. You can go find whatever build you choose. I think you can go straight for 2004 with this guide. My current setup began with a fresh 1909 install. 

2) If you proceed with setup at this point, you will run into the hated Error 12 problem. I recommend for now holding off on all eGPU setup and following the guide here for retrieving the pci.sys file from a Windows 10 1903 V1 ISO as explained in this post: https://egpu.io/forums/pc-setup/egpu-fail-after-update-to-windows-19-03/

  • Basically, what you are doing here is mounting a Windows 10 1903 V1 ISO, locating the pci.sys file, and copying to your desktop or somewhere else (keep it handy and make some backups, in case you need to quickly reinstall Bootcamp or apply this fix to future builds). 
  • You can, however, skip the part of the guide above that tells you to create a bootable Windows stick for dropping the 1903 pci.sys file into your 1909/2004 build on Windows, by purchasing this program: https://www.paragon-software.com/home/ntfs-mac/
  • The NTFS for Mac program makes this super easy, and was the kicker for me: just take the 1903 pci.sys file over to your MacOS partition, and drop it in the relevant Bootcamp folder (Windows\System32\drivers) from the MacOS side. No need to fuss with the USB boot stick stuff.

3) Boot back into Bootcamp, run all Windows updates and all Apple Bootcamp updates. Do this all now, because the next step is to strip any graphics drivers installed during that process. But you want all the other stuff, so do this before we start playing with graphics drivers.

4) Once that is all done, now you can go and download the latest drivers for a MacBook Pro from bootcampdrivers.com, and follow those instructions (be very sure to use the DDU tool to strip bootcamp of the drivers installed in Step 3) to the letter.

5) Once DDU has been run and the drivers installed, you should be ready to turn off the MacBook Pro.

6) Plug in the eGPU while the computer is turned off. No hot plugging or anything like that is necessary. Just turn the MBP on, select Windows to book if you need to, and should boot up perfectly and you will be good to go.

NOTE: On first boot, and some boots after that, you will need to keep the lid open for some reason. 95% of the time I can boot windows and reboot windows with the lid closed. One thing you want to do after logging in the firs time is going into Windows settings and telling it not to turn off the computer when the lid is closed (it doesn't auto-detect the eGPU like MacOS does).

Benchmarks (Include a  CUDA-Z  or  AIDA64  bandwidth pic. Optional: Valley, 3dmark, noting if it's on internal/external LCD )

AIDA64 Bandwidth benchmarks:
Memory Read 2660 MB/s 1110 ms
- Pinned 2660 MB/s 11 ms
- Pageable 1819 MB/s 16 ms
Memory Write 2553 MB/s 1391 ms
- Pinned 2553 MB/s 12 ms
- Pageable 1819 MB/s 16 ms

Comments (eg: how has the eGPU improved your workflow or gaming)

I spent a lot of time messing with Error 12 when I first got the Sonnet Breakaway 550/RX5700XT combo, and I was a bit upset. I had a Gigabyte RX580 Gaming Box previously that literally was plug-n-play in Windows and MacOS and I couldn't understand why. I tried literally every fix on this forum (perhaps poorly following some instructions on hot-plugging etc) but it was always Error 12. Even if hot plugging options with pci disabling worked, that didn't seem ideal to me. 

I tried the pci.sys fix as a last resort and stumbled upon the NTFS Mac/Bootcamp shortcut by accident while trying to create a Windows USB stick. Didn't expect it to work, but it did, and now I have as smooth a Bootcamp eGPU situation as I think is possible. At least it isn't worse than what I enjoyed with my Gigabyte Gaming Box

I am now playing Modern Warfare 2 remastered in 4k at 60fps, DCS World at 1440p with around 50-60 fps (often up to 80 when in the air), and sometimes I can get Star Citizen to run at 30fps without crashing for a full 30 minutes. 

One of the things I've noticed about this setup is that when using an external display, the MacBook Pro dGPU is disabled entirely. And I see my 2.6ghz CPU is boosting consistantly to almost 4Ghz and maintaining reasonable temperatures (though for DCS and other CPU heavy games I tend to disable turboboost and let it rest at 2.6ghz without any risk of throttling after a few hours of play). Basically, I think the eGPU solves throttling issues on the MBP in bootcamp and allows it to compete with higher end dedicated machines as a gaming solution.

Hope this helps some of you! And thanks to all the build guides that helped me piece together my working setup. Keep the faith if you're still bouncing around. 


2018 15" MacBook Pro (RP560X) [8th,6C,H] + Sonnet Breakaway 550 w/RX5700 XT + MacOS 10.15.5 + Windows 10 2004

(Solved Error 12 in both 1909 and 2004 with the 1903 pci.sys file swap, as explained here: https://egpu.io/forums/pc-setup/egpu-fail-after-update-to-windows-19-03/)

2018 15" MacBook Pro (RP560X) [8th,6C,H] + RX 5700 XT @ 32Gbps-TB3 (Sonnet Breakaway 550) + macOS 10.15.5 & Win10 [build link]  

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