That was a hypothetical. What we have is a RB/G 4k instead of an RGB panel. The difference is that an RGB is a “true” 4k display while a RB/G basically uses a panel of half the vertical resolution to pretend to be one.
2x4 grid of pixels on RGB display:
RGB, RGB, RGB, RGB
RGB, RGB, RGB, RGB
2x4 grid of pixels on a RB/G display:
RB, G, RB, G
G, RB, G, RB
Now here is the fun one, 1 RGB line of half the resolution
RBG, RBG, RBG, RBG.
See how 2 lines of RB/G is the same subpixels as 1 line of half the resolution?
The only difference between the 8k “3840x2160” screen and a “3840x1080” screen is that you have split the subpixels into twice as many lines and then driven them like they were different entire pixels.
Now you can either do that directly and that would mean you might miss entire pixels worth of red or blue on a “green sub pixel” so what the driver will do is resample some of the colour information to adjacent pixels causing the blur effect we all know and love. Alternatively you can drive them directly as individual pixels but at best you get the clarity of a 3840x1080 image in any one colour but with gaps where the other colours lie which would lead to worse perceivable SDE on scenes with no green or no red and blue. However this choice will be baked into the panel interface so I doubt there is anything Pimax can do about it. Because of this I doubt the 8kx will look much different at all.
Basically it’s a really dodgy trick to claim twice the vertical resolution with the same number of pixels. Don’t blame pimax entirely though because I have no doubt the device datasheet did not lay out that this is what they were doing. It would have absolutely claimed to be a 4k screen, might even have boasted about not being pentile and any reference to this compromise would have been deeply hidden. Because that’s what LCD datasheets are like for some reason (Given me a headache or three in the past).
Edit for clarity. It’s not all bad. For white on black or vice Versa you do see 4ks worth of lit pixels. However you are actually seeing two slightly offset overlapping 3840*1080 images in different colours hence the slight colour fringe effect. Also the exact pixel resampling technique used puts a hard limit on clarity.
Effectively you get a screen that sometimes looks like a blurred 4k one and sometimes looks like a 3840*1080 one and which you see depends on the exact colours present in the image. Much of the time it will veer between the two. On average with a native source and an optimum resampling technique it “might” achieve an average clarity roughly equivalent to the 5k but I really don’t think it ever will when upscaled.