
While Samsung's latest OLED panels, which are used in the Galaxy S8 and the Galaxy Note 8, can reach a peak brightness of up to 1,000 nits, the iPhone X's peak screen brightness is limited to 625 nits. Unless Apple has limited the maximum brightness deliberately or stated incorrect numbers on its website, there's a chance that Samsung isn't offering Apple its best OLED panels.
Samsung's new high-end phones support the HDR10 format for high dynamic range videos, but Apple's new iPhone X supports both HDR10 and Dolby Vision. It remains to be seen how well the new iPhone's “Super Retina Display” performs in comparison to the Galaxy S8's or Galaxy Note 8's Infinity Display in terms of color accuracy and brightness.