Received my MacBook 2016 yesterday (it is my dream machine!!!) I will update this thread with my experience building an eGPU with Thunder3
My configuration:
MacBook Pro 13" touchbar, i5 2,9Ghz, 8GB RAM, 512GB SSD, Iris 550
Thunder3 modded with Radeon RX480 4GB connected to LG Ultrawide 4K display
Hardware Installation
1. Opened Thunder3 classic (i will need some time to build an enclosure)
2. Put RX480 in place
3. Connected Thunder3 to DA-2 PSU with a modded cable which power both RX480 (8-pin PCie) and Akitio Thunder3 (barrel plug)
4. Connect to Mac
macOS configuration
1. Disabled SIP with csrutil from Recovery terminal
2. Downloaded TB3 enabler to let MacBook Pro use Thunder3 (sadly if you don't want to edit kext there is no way yet since Apple software blocked older Thunderbolt 3 devices)
3. Run new automate-GPU script for macOS 10.12.2+ (coming soon)
4. Optional run script for unlocking all Baffin units to boooooooost OpenCL
Preliminary benchmarks:
I get OpenGL, OpenCL and Metal acceleration, the gfx card is super silent and very fast (and cheap too). There are still issue but i didn't got any artifact connecting it directly to Thunderbolt3.
Valley Benchmark 4K 3440x1440 ultrawide 2x ultra:
Iris 550 5fps - 207 score
Thunder3+RX 480 23.4fps - 980 score
Geekbench 4 GPU:
Iris 550 30584 OpenCL score
Thunder3+RX 480 (with baffin script) 107071 OpenCL score
Luxmark luxball:
Thunder3+RX 480 (with baffin script) 14222
Thunder3+RX 480 (with baffin script) + Iris 550 15423
Cinebench R15 OpenGL:
Thunder3+RX 480 68,70 fps
UPDATE: there are issues with TB3 connection and Radeon cards, so for now i discourage anyone to build this setup. I was able to boot after many many tries. I switched to Nvidia GTX 780ti and it runs fasteeer and boots most of time.
MacBook Pro 2018 Touch Bar i7 quad-core 2.7Ghz - 16GB RAM - 512GB PCIe SSD
my awesome Radeon VII eGPU
my Mantiz Venus extreme mod with Sapphire Nitro+ RX Vega 64
2018 13" MacBook Pro [8th,4C,U] + Radeon VII @ 32Gbps-TB3 (Mantiz Venus) + macOS 10.15 [build link]
Can u try with nvidia gpu over bootcamp windows 10 or 8.1 ??? Thanks
To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.
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Can u try with nvidia gpu over bootcamp windows 10 or 8.1 ??? Thanks
No sorry i just use macOS and this time i want to try Radeon, it should be simpler to get it work, it consumes much less and has only one power cable... and it cost less. I paid RX480 4GB very little last week.
MacBook Pro 2018 Touch Bar i7 quad-core 2.7Ghz - 16GB RAM - 512GB PCIe SSD
my awesome Radeon VII eGPU
my Mantiz Venus extreme mod with Sapphire Nitro+ RX Vega 64
2018 13" MacBook Pro [8th,4C,U] + Radeon VII @ 32Gbps-TB3 (Mantiz Venus) + macOS 10.15 [build link]
Received Thunder3. Opened the case and plugged RX480. Still waiting for PSU and power cable.
Downloaded TB3 enabler 
https://github.com/KhaosT/tb3-enabler
MacBook Pro 2018 Touch Bar i7 quad-core 2.7Ghz - 16GB RAM - 512GB PCIe SSD
my awesome Radeon VII eGPU
my Mantiz Venus extreme mod with Sapphire Nitro+ RX Vega 64
2018 13" MacBook Pro [8th,4C,U] + Radeon VII @ 32Gbps-TB3 (Mantiz Venus) + macOS 10.15 [build link]
First benchmark [RX480 versus Iris550 moved to opening post ]
MacBook Pro 2018 Touch Bar i7 quad-core 2.7Ghz - 16GB RAM - 512GB PCIe SSD
my awesome Radeon VII eGPU
my Mantiz Venus extreme mod with Sapphire Nitro+ RX Vega 64
2018 13" MacBook Pro [8th,4C,U] + Radeon VII @ 32Gbps-TB3 (Mantiz Venus) + macOS 10.15 [build link]
Received my MacBook 2016 yesterday (it is my dream machine!!!) I will update this thread with my experience building an eGPU with Thunder3
Great job! Are you beta testing the 10.12.2+ automate-egpu script?
To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.
.
Nice progress Ikir, could you also run Valley/Heaven in Extreme preset? This is makes it easier to compare between benchmarks.
To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.
.
Sure i will do as soon as i can, probably in 2 days since i'm working 10h/day until sunday!
Yup, it will be released soon, keep checking this website/forum!
MacBook Pro 2018 Touch Bar i7 quad-core 2.7Ghz - 16GB RAM - 512GB PCIe SSD
my awesome Radeon VII eGPU
my Mantiz Venus extreme mod with Sapphire Nitro+ RX Vega 64
2018 13" MacBook Pro [8th,4C,U] + Radeon VII @ 32Gbps-TB3 (Mantiz Venus) + macOS 10.15 [build link]
Nice progress Ikir, could you also run Valley/Heaven in Extreme preset? This is makes it easier to compare between benchmarks.
Heaven Extreme preset 36,2 fps
Valley Extreme preset 36,6 fps
MacBook Pro 2018 Touch Bar i7 quad-core 2.7Ghz - 16GB RAM - 512GB PCIe SSD
my awesome Radeon VII eGPU
my Mantiz Venus extreme mod with Sapphire Nitro+ RX Vega 64
2018 13" MacBook Pro [8th,4C,U] + Radeon VII @ 32Gbps-TB3 (Mantiz Venus) + macOS 10.15 [build link]
Got even better results: Sapphire Nitro + RX 480 has a switch to activate a little overclock.
these are the new results: [ picture in opening post of thread ]
MacBook Pro 2018 Touch Bar i7 quad-core 2.7Ghz - 16GB RAM - 512GB PCIe SSD
my awesome Radeon VII eGPU
my Mantiz Venus extreme mod with Sapphire Nitro+ RX Vega 64
2018 13" MacBook Pro [8th,4C,U] + Radeon VII @ 32Gbps-TB3 (Mantiz Venus) + macOS 10.15 [build link]