Yeah, u are obviously right. I was just doing the dummy math of 1920 x 2 = 3840, and 1080 x 2 = 2160.
Amazing how much of my advanced high school math I forgot over the past 3 decades.
I am still kicking myself for not trying a 4k TV as a computer display sooner. It beats the heck out of my old dual 27" 2560x1440 setup, though I still kept one of the 27's setup on the side in portrait mode for overflow space and to be able to easily access the PC side of things when I am using the TV apps for Hulu, Netflix, Youtube, etc.