Apple's iPad announcements on Tuesday renewed a conflict that has smoldered since the announcement of the iPhone 4: When it comes to "Retina" displays, who has the sharpest, and at what point does it stop mattering?
As displays gain higher and higher resolutions, there's a point at which those pixels are just too small to make out unless you're really looking. Depending on how far you're viewing the display from, it could be around 250 to 300 PPI, or pixels per inch. Apple calls its displays "Retina" when they reach this point, but although Apple helped kick off the trend, it's not the only one with super-high-rez displays.
In fact, competition is fierce when it comes to pixel-dense displays — but not everyone is joining the party. Here's the lay of the land, from lowest to highest PPI.
Oddly enough, although it's Apple's day to shine, the iPad 2 ($399) has one of the least impressive pixel counts out there (and at its age, that's no surprise). 1024x768 on a 9.7-inch screen gives a paltry 131 PPI. The original iPad Mini ($299) applies the same resolution to a smaller 7.9-inch screen, giving 162 — better, but far from impressive.
Between the old iPads and newer devices, you have quite a few Android devices packing 1280x800-pixel or so displays of various sizes, amounting to about 200 PPI. Most of these are quite outdated now (or just not that interesting, like the latest from Sony and Samsung), but you still find them as bargain devices here and there. The Surface Pro 2 ($899) also slots in here with 208 PPI.
Now we cross the vague border between Retina and non-Retina. The fact is there's no magic number, and even on the best screens you can still spot pixels if you look carefully (and if you have good eyesight). But with tablets, assuming you're viewing from about a foot and a half away, the following displays shouldn't show any obvious jagged edges on text and fine lines.
The iPad Air ($499) marks the bottom of the pile here, though as anyone can tell you, it has a handsome screen and text looks great on it. 2048x1536 pixels on a 9.7-inch display makes for 264 PPI.
Next up is Google's Nexus 10 ($399), which adds a few pixels onto the iPad's count while only barely changing the size. 300 PPI is the result — although we're not fans of the tablet's plasticky body.
The Nexus 7 ($229) is much smaller but fits 1920x1200 pixels onto its 7-inch display, making for 323 PPI. Ditto for Amazon's new Kindle Fire HDX 7" ($229 with ads, $244 without).
It's matched almost exactly by the new Retina iPad Mini ($399), which with the same resolution as the iPad but a smaller 7.9-inch screen, achieves 324 PPI.
But the highest-density screen on a tablet you can buy today is none other than that found on the Kindle Fire HDX 8.9" ($379 with ads, $394 without), its 2560x1600 pixels making for a whopping 339 PPI.
For reference, the iPhone 5S, and in fact every iPhone since the iPhone 4, fits in here with 326 PPI. But it and every tablet on this list pale in comparison with the likes of the HTC One, Sony Xperia Z1 and Samsung Galaxy S4, with 1080p screens achieving as much as 469 PPI. And don't think they'll stop there!
But even if there were a tablet with that high of a PPI, would we instantly recommend it over the others? Nope. For one thing, the PPI is only one part of the display's quality — color reproduction, brightness, contrast and many other things factor in. Some screens might look washed out or have visible pixel patterns despite being high-density.
And, of course, there's the tablet itself and its OS. What's the use of Amazon's 339 PPI display if you want to edit video and there's nothing good to do it with on Android? What good is iOS if you want to use your tablet with a mouse and keyboard?
On the other hand, all things being equal, a higher-resolution screen usually means crisper text and sharper images — and even if you can't count the pixels on practically any display over 250 PPI, your eyes may nevertheless be able to tell the difference in a qualitative way.
Your best bet is to head over to your local electronics store and look for yourself. If you can't tell the difference, why pay a premium? On the other hand, you may find you appreciate that high display density more than you thought you would.
Devin Coldewey is a contributing writer for NBC News Digital. His personal website is coldewey.cc.