Apple worked with Blackmagic Design on new Radeon Pro 580-powered eGPU - 9to5Mac
Amazon.com: ASPIRING Video Card RX 580 8GB 256Bit 2048SP GDDR5 Graphics Cards for AMD Radeon RX 580 Series Professional for ETH Mining and Gaming : Electronics
ATI Radeon RX 580 8GB GDDR5 PCIe Graphics Card Mac Pro / PC - Sapphire 11265-67
Amazon.com: ASPIRING Video Card RX 580 8GB 256Bit 2048SP GDDR5 Graphics Cards for AMD Radeon RX 580 Series Professional for ETH Mining and Gaming : Electronics
Amazon.com: ASPIRING Video Card RX 580 8GB 256Bit 2048SP GDDR5 Graphics Cards for AMD Radeon RX 580 Series Professional for ETH Mining and Gaming : Electronics
Apple Genuine 661-03384 Logic Board 4.2GHz i7 Radeon Pro 580 8GB for iMac 27 inch Retina 5K Mid 2017
AMD Radeon Pro 580 Specs | TechPowerUp GPU Database