When Ray Soniera says that PenTile has half of the R, G, & B subpixels as an RGB stripe he is correct. What Dr. Soneira is doing is counting only the R, the G, and the B subpixels… ignoring the W… and ignoring subpixel rendering.
First, imagine that we had a purely monochromatic B&W panel. Do we say it has no resolution because it has no color? (Seriously?) In the PenTile case, each white subpixel would be half of the B&W resolution, and the combined RGB triplet would be the other half. So, it looks like a full resolution B&W display. This is good, because the human eye can see tremendous detail in black & white… But not so well in color!
The human vision system can only see a very low resolution in pure color. In pure red to green color our eyes see only one tenth as well as it can in pure black & white. What we see in everyday life is a combination of pure color and pure black & white, so it seems very richly detailed.
So, having high resolution in black & white, but only half the resolution in pure color, is still more than we need. Why waste putting detail into color which we can’t see?
So, Dr. Soneira is right, we do have only half the number of RGB triplets… but that is a good thing.