2013 15" MacBook Pro (GT750M) [4th,4C,H] + RX 6800 XT @ 16Gbps-TB2>TB3 (Razer Core X) + Win10  

System specs 

MacBook Pro (Retina, 15-inch, Late 2013)

2.6 GHz Quad-Core Intel Core i7

16 GB RAM

dGPU : NVIDIA GeForce GT 750M 2 GB

iGPU : Intel Iris Pro 1536 MB

used the egpu on win10 (as far as I know, mac still doesn't support the 6000 series as they are still new).

eGPU hardware

Razer Core X + SAPPHIRE Nitro+ Radeon RX 6800 XT 16GB GDDR6
Thunderbolt 3 to Thunderbolt 2 Adapter

Thunderbolt 2 cable

Installation steps 

I mostly followed this post :

https://egpu.io/forums/builds/mid-2015-15-macbook-pro-r9-m370x-4th4ch-rx-5600-xt-16gbps-tb2tb3-razer-core-x-macos-10-15-7-win10/

1. downgrade windows to version 1903 (1909 didn't work and I received the error 12)
   I followed this post ( https://egpu.io/forums/pc-setup/egpu-fail-after-update-to-windows-19-03/ ) under "Download any windows ISOs".
2. Disable windows update, unfortunately, I'm stuck in the older version of windows, and I don't want windows to start updating since there are problems in the newer version of windows. I disabled it by running the command "sc config wuauserv start= disabled" in the Command Prompt.
3. download the latest Bootcamp drivers from https://www.bootcampdrivers.com  (In my case, Adrenalin December 2020 Red Gaming edition)
4. In the folder you downloaded, extract DDU  (if not included in future versions, download it directly)
5. Reboot into safe mode (hold shift while pressing reset, After your PC restarts to the Choose an option screen, select Troubleshoot > Advanced options > Startup Settings > Restart. Then when the computer boot, choose option 4 [source : https://support.microsoft.com/en-us/windows/start-your-pc-in-safe-mode-in-windows-10-92c27cff-db89-8644-1ce4-b3e5e56fe234 ])
6. Run DDU, remove drivers for NVIDIA, AMD, and Intel without restart.
7. Reset the computer, hold option so you see the OS picker (Windows and OSX)
8. Plugin the eGPU (both TB2 ports on MBP work), the led lights on the gpu should start working. choose to boot into windows.
9. Open Device Manager, verify your graphics adapter shows up as Microsoft Basic Display Adapter
10. run the "setup" application from the files you downloaded from bootcampdrivers, in order to install the drivers.
    I would recommend watching the video linked in those files so you will know what to do (also how to use DDU if you struggle with it) [ ]
11. at this point, you (hopefully) should be done! I encountered lots of stuttering when I tried to game on the gpu, I read that this can be solved by going Device Manager, find the dgpu, right-click it and then click uninstall device. This solved the stuttering problem for me, this way the egpu is the only gpu that will be in use.

Benchmarks 

Before the egpu playing on the computer was impossible, if it was more demanding than Minecraft, the fps was bellow 10.

now, the games I tested so far works pretty well.

borderlands2 wend from 30-40 fps to ~300fps

no man's sky went from ~7 fps to 70-90 fps

I also tried VR on my oculus quest (wirelessly with virtual desktop, didn't try using a link cable).
Half-Life: Alex works great for me. one of the games I look the most to play.

overall, the performance is not as great as the card is capable of, it is limited by the thunderbolt2 connection, but this is to be expected.

Comments 

I would not recommend it :

• I am stuck at an older version of windows,  and can't upgrade
• No support (hopefully, yet) for 6000 series on macOS
• sometimes the audio doesn't work, but I found that connecting my headphones to my USB mic's 3.5 jack worked.
• performance is lower then the card's capabilities.

On the other hand, I am able to game on my computer now.

But if you don't have the hardware already, you probably be better off building a new PC.