2015 15" MacBook Pro [4th,4C,H] + RX 580 @ 32Gbps-M2 (ADT-Link R43SG) + macOS 10.15.1 & Win10 1903 [itsage]  

Congrats for the amazing build, @itsage! You're really tech savvy! Now, I wonder if you could help me...

I have the same MacBook Pro you used here – Mid 2015, 15", iGPU, 2.2Hz, 256GB SSD and 16GB (plus an RX 5700 XT + Razer Core X, fully operational on both OSX and Win10/Bootcamp).

I want to upgrade the current 256GB SSD to an 1TB one (using a Sintech adapter). But I don't know if the eGPU is going to work properly on Windows 10 via Bootcamp using third-party SSDs. I've read over the internet some issues when installing and using Win10 in this context.

Although your build is different from mine – I intend to just replace the current SSD with the new one, instead of putting it externally as you did – it's the closest I've found. So I was hoping if you had any idea if your successful setup is a sign the plan of upgrading my SSD may work alongside Win10. Any help is appreciated!

P.s.: I haven't choose the NVMe SSD yet, maybe a WD SN550, Samsung 970 EVO Plus or Crucial P2.

@ian812, I actually installed a Samsung 960 EVO NVMe drive in this 2015 15-in MacBook Pro. It's been working great in both macOS and Windows as well as with eGPU (via Thunderbolt 2 port). I used the stock 256GB drive for this build because the drive was already in the external adapter.

@itsage, so you're using both SSDs at the same time? Amazing.

Now I'm considering buying a Samsung NVMe SSD, after your successful build 🙂 (maybe they're safer because Samsung also manufactured the stock SSD?). However, I read here that Samsung NVMe SSDs have higher power consumption than similar models from other brands. As I never disconnect my MBP off the charger due to the eGPU, I don't know if this is an issue at all. What do you think? Thanks for the help!

@ian812, I have the Samsung 960 Evo installed in the internal drive socket and use the laptop that way most of the time. The original 256GB drive is in the external drive enclosure come to use when I need to open the laptop for M.2 eGPU.

From memory, I formatted the NVMe drive then did clean install of macOS (through a USB installer). Once that was done I proceed to install Windows through Boot Camp Assistant. I have not noticed any reduction in battery run time with the Samsung drive.