GTX1070 via a TB2->TB3 adapter on a 2015 MacBook pro, with Windows installed on the SanDisk extreme ssd. It's working amazing! : r/eGPU
eGPU Macbook Pro + GTX970 + Akitio Thunder2 case - YouTube
display - When using an external monitor, does a mid-2015 Retina Macbook Pro with only integrated graphics run cooler than one with discrete graphics? - Ask Different