Rumor has it that the next iteration in Samsung’s Galaxy S line of phones will come with a QHD display. Commonly referred to as “1440p,” QHD is Quad HD, or a resolution of 2560×1440. At around 5 inches, a display with a QHD resolution comes out to a pixel density of 587PPI. Considering our current ~450PPI displays look fantastic as it is, it certainly sounds like overkill. But there is an argument to be made for such a high-density display.
Joshua Ho from Anandtech published an article last weekend going over the math and science behind screen resolutions, pixel density and the human eye. This has been covered in detail before, but with rumors of Samsung using a QHD display on the Galaxy S5 swirling, it seems pertinent to revisit the subject.
I highly recommend you read the entire article found at the source link below, but the gist of it is that to get the full story on indistinguishable pixels, we need to look at display resolution and how far away from your eye a display is held, measured in pixels per degree (PPD). By doing the math, Ho found that technically anything under 600PPI is not overkill. There are cases in which pixelation would be detectable at even the current 450PPI available on most high-end smartphones today. That means that Samsung’s ridiculous-sounding 2560×1440 display may not be so ridiculous after all.
Case closed, right? Not even close. That’s really only half the story. Yes, the human eye may theoretically be able to tell the difference between a 450 and 600PPI display being held 12 inches from your face, but is the incredibly minute difference worth it? Utilizing all those pixels means using more processor and battery power. The popular opinion is that the best smartphones have the best balance. Personally, I’d rather have a phone with a 1080p display that lasts a full day and a half on one charge, is impressively fast and has a small footprint over a bigger, slower phone with a QHD display that struggles to make it through a single day.
To answer the question of whether or not a Galaxy S5 with a QHD display would be overkill, we’ll have to see just what Samsung can do with the S5. If it is slower, bigger and has poor battery life, I think everyone will agree that it is overkill. If the S5 manages to boast the same numbers in performance and size as the S4, people will be torn. I might think, just how much better could everything else have been is Samsung had gone with a lower resolution? You might think, who cares? It’s plenty fast and has the best display on the planet. If Samsung is able to up the display resolution and improve on everything else the S5 has to offer, well, I don’t think there will be much to complain about. Mathematically, a 600PPI display isn’t necessarily overkill, but we’ll have to see what Samsung can really do with all those pixels for it to really matter.