Below I lay out a possible case for 4K video on the iPhone 6. Before we begin, allow me to define what 4K video means in this context. I'm referring to consumer 4K, which is 3840x2160 (16:9) running at 30fps. There are a few hardware related reasons why we might see 4K in the upcoming iPhone 6: Much faster A8 processor Base-level storage increase Optical image stabilization Following the trend year over year, using a synthetic benchmarking software such as Geekbench, we see iPhone speeds nearly doubling (or even tripling) year over year using the multi-core scores tab: iPhone 4: 206 iPhone 4S: 406 iPhone 5: 1276 iPhone 5S: 2378 Eventually mobile chips will hit a wall much like desktop processors, slowing their growth considerably. But I'm not quite certain we're there yet. There's also an outside chance that we might see a quad-core A8, although I admit the possibility is more likely in an upcoming iPad or iPad Pro model. Even so, we should see considerable speed improvements with the A8 processor, which would allow for higher rates of video capture. Combine this with Apple's purchase of Anobit a couple years ago, and we might start seeing much increased NAND (flash) memory speedsmuch like we saw the benefits in their A-series processors a couple years after they bought P.A. Semi in 2008. These increased NAND speeds would be able to more easily cope with the high-speed writing and reading operations of 4K. Speaking of NAND, the rumored base-level storage increase also points the potential for 4K video. If the iPhone starts at 32GB and also comes in 64GB and 128GB sizes, the iPhone would now have much more capacity to store larger 4K videos. iCloud Drive in sizes up to 1TB would also go a long way towards easily pushing large video files off of your device, but at the cost of massive data usage (and long upload times) that would absolutely be limited to WIFI. The last rumored piece of hardware that points to 4K video is optical image stabilization (OIS). When recording video at such a high resolution, even small hand movement negates much of the benefit of the increased resolution because it causes motion blur on a smaller scale. Having OIS in the iPhone 6 would provide fairly sharp 4K video. Now that we've talked about the hardware, let's briefly talk about the software. Apple has been buying up companies that specialize in faster image recording, and posting many job positions for experts in this field. It's quite possible that they could further optimize their software to record images even faster, negating at least some of the need for faster hardware. I'm about to jump into the numbers, but first let's talk about slow-mo video capture. When the 5S was announced, I found it interesting that the slow-mo features was limited to 720p at 120fps. They were really pushing the hardware as far as they could go. Many people (myself included) have thought that the iPhone 6 would likely bump this up to 1080p at 120fps. Surely with the A8 chip, optimized software, and everything else they can do it, right? Let's look at the numbers. Hopefully my math is correct! iPhone 5S 720p 120fps: 110,592,000 pixels/s 720p 240fps: 221,184,000 pixels/s 1080p 120fps: 248,832,000 pixels/s 2160p (4K) 30fps: 248,832,000 pixels/s Interestingly enough since 4K video is double 1080p in width and height (therefore 4X the number of pixels), but running at 1/4 of the frames per second, they end up running at the exact same fill-rate of 248,832,000 pixels/s. Neato. Another fun fact is that 720p at 240fps is a lower rate than 1080p at 120fps, so perhaps in the slow-mo interface of the camera app, they could have it default to 120 and have a button toggle for 120/240? And the fill-rate is roughly twice as much as 720p in the 5S, so if the 6 is twice as fast with optimized software then it may be able to handle it. Another possible benefit we could see is pixel-doubling video. I'm not sure if it's a bandwidth issue, but the iPhone currently only pixel-doubles photos in lower-light conditions for photographs and not video. This halves the resolution, but boosts the light sensitivity. In theory if you can now record 4K video then you could also record 1080p video with much greater light sensitivity. So what do you guys think? Will we see 4K video on the iPhone 6? Or will Apple take their time, in typical Apple fashion, because the 4K TV market has yet to take off? I for one would like to have 4K for future archival purposes. I just had my first child a few months ago and most of the video we take of her is on our phones. It would be great to be able to play them back on our wall-sized TV when she is older without them looking very pixelated. I know, first world problems!