Here’s Why PS4K’s Ace Will Be HDR Support, More Than Any Resolution Boost
Ever since the leaks began around PS4K, there's been a lot of speculation regarding this supposedly enhanced version of Sony's PlayStation 4. While it's not yet official by any means, there have been too many rumors from different sources not to believe that there's something real behind it all.
However, the code name itself might lead some to believe that PS4K's biggest achievement may be running games at 4K native resolution. This article looks into debunking such belief and showcasing the true ace in the hole of PS4K.
Even if the most recent rumor suggesting a GPU two times more powerful than PS4's turned out to be true, we would still be quite far from the raw horsepower needed to render games natively at 4K.
The current version of Sony's console outputs most games (unlike Microsoft's Xbox One) at a native FullHD resolution, or 1920x1080 (1080P), which is equivalent to 2,073,600 pixels; conventional 4K (3840x2160), on the other hand, requires four times the number of pixels (8,294,400). Right now, there is no single GPU capable of handling 4K rendering in performance intensive games while maintaining 60 frames per second; it is speculated that the most powerful GPUs from AMD and NVIDIA of the upcoming generation, Polaris and Pascal, might be able to do so.
But those high-end graphics cards will cost $500/600 at release, and it's a known fact that consoles use mid-range GPUs to keep the price down. A much more realistic goal would be to increase the native resolution from 1080P to 1440P (2560x1440), or 3, 686, 400 pixels. That would translate into a 77% increase over 1080P in terms of pixels and definitely something that a GPU twice as powerful as PS4's could handle.
The 1440P native resolution would then be upscaled to 4K, of course, but don't expect earth-shattering graphics improvements in this case scenario; in fact, some of the less tech savvy customers may barely notice it. Does that mean PS4K won't have any appeal for enthusiasts? Not at all, as the biggest technical advancement may well be another one: HDR support.
High Dynamic Range rendering has been used in games for many years now, but display technology has severely limited its results until now. That's because even the best HDTVs have been stuck with the Rec.709 standard, first approved in 1990. Now this is all changing thanks to the push for Rec.2020, approved in 2012 for UHDTVs (4K and 8K) and supported by the HDMI 2.0 standard. First of all, Rec.2020 says goodbye to interlacing, thus only allowing progressive scan frame rates.
More importantly for our topic, Rec.2020 is defined by a 10/12-bit color space whereas Rec.709 was limited to 8-bit. With the introduction of Wide Color Gamut support, we'll be able to see over a billion possible colors with 10-bit while we have been stuck at 16 million with our current 8-bit displays.
They say that a picture is worth a thousand words. In the one just above, Rec.709 is represented by the smaller triangle while Rec.2020 is the far bigger one inside the CIE 1931 curve of colors that humans can perceive.
Wide Color Gamut goes hand in hand with HDR. In fact, it is no coincidence that the HDMI 2.0a revision added HDR support and Polaris (the new AMD architecture upon which the PS4K's GPU may be based) has been confirmed to have HDMI 2.0a support.
Those of you who followed CES 2016 closely already know that HDR had its heyday in Las Vegas this year. All of the major display manufacturers (including Sony) committed to the technology, while Netflix, Amazon, YouTube and Vudu have announced more HDR video content coming to their streaming services. But what is HDR, exactly?
It is the ability to display much brighter and much darker pixels whenever necessary, allowing for far more contrast between bright and dark spots in a scene than we're used to. Rec.709 confined displays to a luminance between 0.1 to 100 nits, while Rec.2020 allows a much greater variance - from 0.0001 to 10.000 nits, in theory.
The slides above are taken from a Build presentation hosted by Microsoft. A very similar one took place at GDC 2016 and the content was essentially the same: Microsoft is a big believer in HDR and Wide Color Gamut support. According to their tests, it's a more noticeable improvement to end users than 4K resolution and they will be adding support for both technologies to Windows 10 in 2017.
They aren't the only ones, though. AMD itself made a big deal of their push for HDR during CES 2016 in what they called the Better Pixels Initiative.
A couple of the slides from that report will be quite useful once again. AMD went as far as saying that 1080P+HDR looks better than 4K+SDR (Standard Dynamic Range), as you can read below; of course, it goes without saying that 4K+HDR is the superior option.
The other slide is an example of SDR versus HDR. Given any source content, the difference between the two will be similar to the image below.
Of course, developers will have to make adjustments, but Microsoft said in the aforementioned Build presentation that it will be fairly trivial to add HDR & Wide Color Gamut support for those who are using a PBR pipeline. That's because a lot of the HDR data is already being generated, it's just not displayed; Microsoft estimates that the actual engineering work may be even less than a week.
The good news is that there won't be any performance cost for games. The bad news is, as you should have guessed by now, that an HDR compatible display will be needed. In case you were planning to buy a 4K display right now by taking advantage of some particularly enticing offer, with the idea of being ready when the PS4K ships, don't. As explained earlier in the article, despite the name that's been circulating it is highly unlikely that games will be rendered natively at 4K resolution for obvious performance reasons and you would be left without the truly major advancements in graphics, HDR & Wide Color Gamut support.
You will be able to recognize displays that have both technologies if they sport the UHD Premium badge, which has been chosen by the UHD Alliance as the official label. To be thorough, there will be two UHD Premium standards: displays with 0.05-1000+ nits will be classified in the Standard 1, while those with 0.0005-540 nits will be in the Standard 2. That's because LED displays allow for better peak brightness but less deep blacks (Standard 1), while the reverse is true for OLED displays (Standard 2).
PS4K is rumored to launch in Q1 2017, which is when many more UHD Premium displays will be available and also when Microsoft plans to deploy HDR & Wide Color Gamut support to Windows 10. Needless to say, Sony would gain a huge advantage in the console market among enthusiasts until Microsoft and Nintendo can offer the same with their consoles.