GSM Arena: The Samsung Galaxy S4 sports a 4.99-inch Super AMOLED display with a 1920×1080 pixel format. If the sub-pixel structure is RGB then resolution can be calculated at 441 ppi, but there is a chance the sub-pixel structure might not be RGB and therefore resolution not as high as 441 ppi.
Update 2013.04.24: Reviews are in, and the sub-pixel structure is not RGB. According to AnandTech, Samsung is using yet another sub-pixel format for the Galaxy S4:
There’s still a bias toward more green subpixels than blue or red, this isn’t an RGB stripe at all, but instead of the previous RG,BG layout we see this offset pattern with green on one line, then blue and red on another line. Interestingly enough the blue subpixel appears to be a square, and red and green appear to be circles, with the difference in area possibly offsetting the luminous efficiency of each material.
David Pierce, The Verge:
The GS4’s 5-inch, 1920 x 1080 display is big, beautiful, and seriously eye-catching. The latter is partially a bad thing: the S4 uses a Super AMOLED panel like many of Samsung’s phones, and like many of Samsungâ€™s phones it displays overly contrasted and vibrant colors. Those colors may not be accurate â€” reds and oranges absolutely explode off the screen, whether they should or not â€” but they certainly catch your eye. And with a ridiculous 441-pixels-per-inch, even the PenTile display matrix I usually loathe causes no problems.
Catchy versus accurate colors? I prefer the later. The resolution of 441 ppi is not correct since ppi assumes a RGB sub-pixel structure. I’m also not certain this version of the PenTile sub-pixel structure exhibits no problems; we will know for sure when Raymond Soneira publishes an in-depth display technology shoot-out article comparing the Galaxy S4’s OLED display tomorrow morning.
Update 2013.04.25: And here it is. The definitive word from Ray Soneira:
But for digitally generated fine text and graphics with precise pixel layouts the eye can visually detect the reduced number of red and blue sub-pixels unless the number of red and blue sub-pixels per inch is very high. And it is for the Galaxy S4 â€“ there are 312 red and blue sub-pixels per inch, which is only a few percent lower than Appleâ€™s benchmark 326 PPI iPhone retina display. Visually the Galaxy S4 PenTile display delivers excellent visual sharpness across the board.
There you have it: When it comes to visual sharpness the PenTile OLED display on the Samsung Galaxy S4 is about as good as the RGB IPS LCD on the iPhone. The result of the shoot-out? A tie:
The iPhone 5 is significantly brighter than the Galaxy S4, particularly for screens with mostly peak white backgrounds. Its color calibration is a bit better, although the Galaxy S4 has a more accurate white. The Galaxy S4 has a much bigger screen, higher resolution, higher PPI, much darker blacks, and better screen uniformity than the iPhone 5.
Color accuracy has always been a sour point for OLED displays, but the Galaxy S4 at least has an option: If color and image accuracy are most important Soneira recommends Movie Mode, which provides “very nice, pleasing, and accurate colors and picture quality.
Apple iPhone display engineers have some work to do: improve white accuracy, deepen blacks, and enhance screen uniformity.