The DP1.4a supports maximum 4K at 120fps, everything above that is using DSC (display stream compression).and if I am not wrong adds a bit of latency and a bit of processing overhead, because your GPU has to compress the frames. Additionally the compression adds some loss to the equation, but according to reports it is very hard to distinguish it from the lossless picture.

The bottom line is that if I shed north of 1K I would like to get something which is future proof.