While not a true solution because you need to break open your computer, the newest iMac Pro has socketed DDR4. iFixIt’s teardown[0] suggests the max it’ll suppo

While not a true solution because you need to break open your computer, the newest iMac Pro has socketed DDR4. iFixIt’s teardown[0] suggests the max it’ll support is 4x32 GB for a total of 128 GB. [0]: https://www.ifixit.com/Teardown/iMac+Pro+Teardown/101807 https://www.ifixit.com/Teardown/iMac+Pro+Teardown/101807