Originally Posted by TLZ
It's not 4k60 on the X. And both the X and PRO have the exact same performance. Both go between 55-60Fps.
The resolution bump on X is nice though.
DF also stated the One X version is leagues ahead of the Pro in texture filtering especially in floor textures and shader adjusters.
You can check this out starting at 4:40 in the DF comparison vid.