It wasn’t too many years ago that the smartphone resolution wars were in full swing. The debate raged over whether Apple’s Retina Display jargon actually meant anything, while Android phones raced from Full HD (FHD) to Quad HD (QHD) resolutions. Sony even went as far as to push the 4K narrative for our tiny phone displays. Fortunately, that’s a mobile trend that hasn’t caught on (yet).
In a complete U-turn, the industry today is much more relaxed about the display clarity argument. In fact, several high-profile 2020 and 2021 releases don’t bother with the flagship QHD resolution that we’ve become accustomed to. The Samsung Galaxy S21 and OnePlus 9 are content with “just” FHD+ resolutions.
Do these handsets offer an inferior display experience or has the industry settled the Quad HD vs Full HD debate and picked FHD+ as the clarity sweet spot?
Do you really need Quad HD?
The selling point of Quad HD displays is sharper images and improved clarity. This is more important for larger displays, where a greater number of pixels are required to keep up the pixel density and thus clarity. Pixel density is often referred to as the pixels per inch or PPI number. A higher display resolution also helps games appear smoother with fewer jagged edges. Although rendering more pixels puts more strain on the graphics processor, potentially lowering the frame rate and/or consuming more power.
However, there is a limit on the level of detail that the human eye can see for a given viewing distance. There’s a lot of variables to the science behind human visual perception limits, including the size of the screen and viewing distance. For a small 5-inch smartphone, an FHD resolution has you covered pretty much regardless of how close you hold your device. For larger 6-inch and 7-inch handsets, the move from FHD+ to Quad HD can make a little bit of a difference at closer viewing distances.
The graph below plots roughly the maximum pixels per inch you can see for a given distance in yellow. I calculated the PPI for these distances using the equations you can find here. The PPI offered by various resolutions for three unique display sizes is shown in the column plots.
For devices between 6 and 7-inches in size, the crisper density of QHD is just about noticeable when holding phones closer than 30cm from your eyes. The key takeaway is that higher resolutions are only just noticeably better on the very largest phones held very close up. However, most consumers probably don’t hold their smartphones so close. 30cm to 40cm is nearer to a typical handling distance so even FHD has you covered virtually regardless of device size at those sorts of distances.
It’s also worth noting that wider aspect ratio FHD+ displays found in modern devices sit as a nice middle ground between 16:9 FHD and QHD devices from previous years. At typical viewing distances, even large FHD+ phones, including the Motorola Edge Plus, end up right in the sweet spot where we’d struggle to notice any further increase in resolution. The latest high resolutions found in the likes of the Samsung Galaxy S21 Ultra fall well beyond our visual abilities even for very large mobile screens.
FHD+ is as good as your eye can see for all but the largest phones at very close viewing distances.
Another important point is the resolution of content viewed on your smartphone. The majority of video content streamed online is still 1080p (FHD), or perhaps even 4K. Playing back at a native resolution looks best, or failing that, scaling up or down by a nice integer factor. For example, 4K is 4 times the resolution of 1080p, so it scales nicely for good-looking playback. QHD or 1440p doesn’t divide exactly into 4K or 1080p, meaning that playing back this type of video content actually looks blurrier on a QHD display than it does on an FHD panel.
In a nutshell, the move to QHD and beyond is a case of diminishing returns and it definitely has its share of trade-offs too. Particularly when it comes to battery life.
Quad HD vs Full HD: battery life tradeoffs
The biggest trade-off with the move to Quad HD and QHD+ has increased power consumption. There aren’t just more pixels on the display to power, but your phone’s graphics and display processors have to work harder too. We’ve tested this thoroughly in the past, so check out the article below for the details, as well as this newer look at 2020’s Galaxy S20 Ultra.
Full HD vs Quad HD: How much does 1440p really affect battery life?
In summary, powering a Quad HD display consumes roughly 12 percent more power than Full HD. Using Quad HD has the biggest drain on battery life when playing games, followed by watching videos. Flicking through the UI and browsing the web is less strenuous on processing components, and thus less affected by higher resolutions. As you’d expect, setting your phone to a lower display resolution helps improve battery life but not always by a lot. This is mostly beneficial for lowering power consumption when playing games, as the display still has to power those extra panel pixels regardless.
Fixed Full HD hardware saves more battery than lowering the resolution of a Quad HD panel.
Of course, the growth of high refresh rate display is another improvement to image quality that knock-on effects for battery life. Typically speaking, picking Full HD over Quad HD adds over 30 minutes to screen on time or possibly even more for gamers. Although this varies a lot from handset to handset.
Manufacturers disable Quad HD anyway
Although we still see very high-resolution displays on modern spec sheets, most consumers probably aren’t using their phone at that resolution. At least not out of the box.
Although many high-profile flagships boast QHD+ capable displays, they are actually set to an FHD+ resolution in software out of the box. Just check the display settings on virtually any high-end smartphone release, such as those in the Samsung Galaxy S21 series, and you’ll find the phone set to FHD+ by default.
While flagship smartphones continue to offer QHD+ hardware, many manufacturers have decided that setting their displays to FHD+ offers the best balance of visual clarity and power consumption. The fact that few consumers have noticed the downgrade from QHD to FHD+ is a testament to how small the difference really is. That said, Quad HD is a nice feature to have if you really want your display to look its very best.
More about displays: Why not all 120Hz phones are equal
What’s the minimum you should buy in 2021?
If you’re spending money around and above the $1,000 mark then you should expect nothing but the very best. For a large phone around the 7-inch mark, that would be a QHD+ display combined with a big battery so that you can run the panel at its full resolution for the whole day. Otherwise, FHD+ is the best option for smaller handsets.
That being said, resolution certainly isn’t the be-all and end-all of display quality. In fact, 120Hz refresh rates as well as classic metrics such as gamma accuracy, color, and white balance, have a bigger overall impact on image quality. Full HD+ is more than clear enough in the vast majority of use cases and for all but the largest smartphones. In fact, it’s pretty close to the older QHD resolution and most flagship phones now default to FHD+ out of the box anyway.
The industry seems to have settled on FHD+ resolutions as the sweet spot. But do you agree with that assessment?