Based on tftcentral review, hdr contents via hdmi that are mastered at 1000 nits can only be shown at 600 nits if the reference white setting is set to 80. To properly display those at 1000 nits, we need to either increase or decrease the setting. However, decrease it to 52 will make 100-400 nits content darker than they should be and increase it to 168 will make those contents brighter than they should be. Anyone here will a game console can test and see what is the optimal reference white so that all luminance levels are correctly displayed? It's weird this does not happen to displayport and setting reference white to 52 will display everything as intended. Reply from Asus rep will also be appreciated.