So you would like to use a powerful desktop class graphics card with your laptop? The Sonnet eGFX Breakaway Puck has you covered. It lets you connect an AMD Radeon 570 GPU to your computer with Thunderbolt 3 ports. The enclosure measures 6 inches wide by 5.1 inches deep. The Puck provides 45W of power.
The Puck has 3 Display Ports and one HDMI port, so it can supports 4 x 4K displays. It is compatible with Windows and macOS computers.