So I commented in the thread "5k iMac" asking a question, but nobody responded so I figured I could ask it in a new thread. As I understand it you can't use an <gs id="41d5171d-2f52-4d2d-b3e3-6725ec0aba5e" ginger_software_uiphraseguid="3e25d2a8-4b9e-4bb3-a8db-7b7c8e954d65" class="GINGER_SOFTWARE_mark">eGPU</gs> on a 5k <gs id="68176b1a-d112-4e13-8709-14268b5b3158" ginger_software_uiphraseguid="3e25d2a8-4b9e-4bb3-a8db-7b7c8e954d65" class="GINGER_SOFTWARE_mark">imac</gs>, the only way it would work if I would use it on an external monitor. So wanted to ask, is this just a dedicated GPU issue? Or thunderbolt 2 doesn't have enough bandwidth. And if so, in any future retina <gs id="c645a1db-706c-4120-bed8-56ca120dc65e" ginger_software_uiphraseguid="2cf6e055-f3ed-4acf-8e3d-30a169b77a06" class="GINGER_SOFTWARE_mark">imac</gs>with thunderbolt 3, will it work with the internal screen? I'm interested in adding some boost to gaming and editing and if it works with thunderbolt 3 I can wait a year to get the next one.