2015 27" iMac 5K (R9 390) [6th,4C] + RX 5700 XT @ 16Gbps-TB2>TB3 (Razer Core X) + macOS 10.15.7 & Win10
System specs: iMAC 27" - late 2015, i7 4.0, dGPU - Radeon M390 2Gb, iOS Catalina 10.15.7 + Windows 10 1903 - build 18362
2. Tried to play a couple of games with eGPU in 4-5K resolution in iOS - everything is working
3. Installed Bootcamp Windows 10 - build 18362
4. Created automate-eGPU EFI boot USB under iOS - easier
5. Turned off eGPU. Boot into Windows with EFI USB. DSDT overrun, large memory in device manager appeared
7. Turned off the computer. Turned on eGPU
8. Started Windows with dGPU and eGPU together - a couple of reboots as AMD X Connect asked me to do it
9. Disable Windows updates. Open Windows graphics preferences and put the apps/games you want with the best performance
Benchmarks - to be continued
The results are not great with an internal monitor.
3DMark said it will be low with such indirect connection.
I connected directly with HDMI cable to my TV - 65" LG, not ideal, but I don't have a 2nd monitor to check it out.
The results on external TV are a bit better.
Comments - all games are installed on external Seagate HDD 4Tb (low speed, yes, I know)
RDR2 game is not happy with 2019 drivers, FPS~20-30 on Ultra settings with 3200x1800 resolution
GTA5 - FPS~50-60
Cyberpunk 2077 - ok
I need to upgrade either my internal iMac SDD or find external SDD
Also, I want to try to install new drivers from Dec 2020 - see what is going to happen