Is it possible to disable the dGPU on a 2017 15-inch MacBook Pro?
I would like to disable my dGPU (Radeon Pro 560) on my 2017 15" MacBook Pro. The reason being is that (I believe) it would help freeing up resources (PCIe bandwidth) for my Thunderbolt 3 devices. Currently I have a Razer Core X with a XFX 5700 XT Thicc III installed on it plugged into my MacBook (TB3 top-right port, Thunderbolt Bus 1) and I also have a Thunderbolt 3 SFP+ Adapter (QNAP QNA-T310G1S) connected to my MacBook (TB3 top-left port, Thunderbolt Bus 0) and on my experience I am being bottlenecked by the limited bandwidth available for my PCIe devices.
When I boot my MacBook Pro using a LiveCD (like PopOS or Ubuntu) I have more control of which devices I want enabled (I can disable the 16x PCIe slot where the dGPU sits on) and I am not being bottlenecked at all, my iperf3 tests always max out 10Gbps on the 10G Ethernet adapter and the bandwidth for my eGPU (H2D) is way higher than what it is on macOS.
I don't want to use my Radeon Pro 560 for anything, when I am on the go using my MacBook I am okay with Intel Integrated Graphics but when I am at home using my Thunderbolt 3 devices I want some extra performance that I am not getting due to (I believe) the lack of bandwidth available for the PCIe lanes.
I can also proof that theory on Bootcamp, which also gives my the ability of disabling PCIe slots/devices and help increase the bandwidth for PCIe/Thunderbolt3 devices.
TL;DR: Can I disable a PCIe slot or even a PCIe device (Radeon Pro 560 in this case) on macOS? I have rEFInd installed and working, so maybe there is something to tweak in there?
My MacBook specs are:
Radeon Pro 560