2014 15" MacBook Pro (GT750M) [4th,4C,H] + RX 570 @ 16Gbps-TB2>TB3 (Sonnet Breakaway 550) + macOS 10.14.3 [briantium]
Hardware pictures (tba)
Followed purge-wrangler and purge-nvda steps to enable this set up to work. Also needed SwitchResX app to enable the set up to work in clamshell mode and not power both screens (which caused serious lag until I used the app and got it to work exclusively on the external monitor).
Unigen Valley (Custom, Ultra, 8x Tesselation, 1440 x 900):
Nvidia 750: 13.9 fps; 583 score
Radeon 570: 35.5 fps; 1484 score
Unigen Heaven (Extreme preset):
Nvidia 750: 11.3 fps; 284 score
Radeon 570: 30 fps; 755 score
Cinebench Open GL:
Nvidia 750: 59.36 fps
Radeon 570: 58.95 fps (not a typo; one second less than the internal 750)
Bruce X (FCPX):
Nvidia 750: 2:40*
Intel Iris: 1:10
Radeon 570: 51 seconds
Comments The eGPU definitely improves graphics performance.
*I'm assuming the poor render time on the Nvidia has to do with Mojave no longer supporting Nvidia cards? I mean, I see that it's working on the GPU History panel in Activity Monitor, but it's definitely poorer than when BruceX was ran on Sierra 10.12.6 (1:25 on that OS; High Sierra was 3:09).
You can also look up my other build with my new 2018 Mac Mini i7 on this forum: Running the same setup on that computer yielded times that were consistently about 26% faster thanks to the TB3 cable; for example, I exported an old project that took 2:09 on the 2014 MBP but took 1:35 on the Mac Mini. So for those who are curious about the performance hit running an eGPU on a T2 computer versus a T3 one, there you go.