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Understand How PS4 Pro Does Native 4K / Upscales Games to 4K and Why Difference is Hard to Spot
PS4 Pro has been in the market for a while now, however, there is still some confusion among the gaming community over the capabilities of this upgraded console, like can it do native 4K or it upscales them? If it upscales, how does it do it?
The answer to the aforementioned questions is bit complicated and requires a certain level of architectural knowledge of PS4 Pro. You will find some games that will run at native 4K on PS4 Pro but they are rare and the majority of the games are upscaled to 4K.
However, the important thing is that it is hard to find the difference between a PS4 Pro game running at upscaled 4K and a game running at native 4K. How this upgraded console does it? Let me explain!
First let’s talk what is upscaling. Many of you have might have experienced it while playing a basic PS4 game on a 4K TV and the game is being upscaled to 4K. In this situation, the upscaling is being done by your TV, which is receiving a picture consisting of 2 million or so pixels and stretching them to fit 6 million pixels as it sees fit.
If you are playing a PS4 Pro game on a 4K TV then the upscaling is being done by the console and generally speaking the console does a better job of upscaling than the TV.
However, PS4 Pro goes a little further than simple upscaling the game to 4K resolution and that is why it is hard to differentiate from native 4K while making a mockery of a simple upscale technique of a 4K TV.
Now the games designed for PlayStation 4 Pro usually target a higher resolution than 1080 which means fewer pixels that need to be filled in the upscaling process. Also, the console also uses a technique called ID buffer which tracks the edges of the in-game object as they are being upscaled.
Now the architects of PS4 Pro have implemented two additional techniques that make use of the ID buffer. The first of the two techniques is an advanced form of Geometry Rendering which is designed to make the edges of the in-game objects look detailed and crispier and most interestingly, without the need of requiring much of the processing power.
The second technique is Checkerboarding, about which you might have heard a lot. The reason PS4 Pro requires Checkerboarding is that Geometry Rendering alone is not enough. While Geometry Rendering makes the edges crispier making them look like native 4K but the objects remain in their native resolution which is quite lower.
You must be wondering why Geometry Rendering is important if Checkerboarding is one that does all the work. Well, the answer is simple, this not only makes the in-games objects much more detailed but has a huge effect on the game’s aliasing which can make the telephone wire, looking like a sequence of steps, into a smooth and greatly defined line.
While you will get the sharpness through the use of Geometry Rendering but without Checkerboarding, you will not be seeing any difference in the textures between the edges which are just as blurry as they were in their native resolution.
Checkerboarding is a bit complicated technique and I will try my best to explain it as simply as possible. This technique does not even use the standard pixels, instead it makes use of “exotic” pixels where each pixel contains one color, and each exotic pixel is equal to the width of two standard pixels.
Exotic pixels calculate the color in twice the number of locations than a standard pixel which helps to fill the empty pixels more sufficiently. Now each “Exotic” pixel has two z values, which calculate where the pixel will be placed in the 3D plane and two IDs which track the object.
While the “Exotic” pixel is making the color appear in twice the number of locations than a standard pixel, the “Z” and “ID” are calculated as if they are in native 4K. In Mark Cerny’s own words, not only Checkerboarding makes the edges super crisp over Geometric Rendering but it also adds internal details in various ways.
So, what does Checkerboarding adds that Geometric Rendering doesn’t? Well, with Checkerboarding implemented, you can make out the individual teeth on the characters and other minor details will become significantly prominent that would have been otherwise ignored in a 1080p resolution.
However, the important thing is how the game looks in real-time using these techniques on a PS4 Pro, as any game can look good in a still image.
I can assure you that running games on native 4K and Checkerboarding side-by-side, it is very hard to spot the difference and in some cases, you will need PS4 Pro architect Mark Cerny to point out the difference for you. That is how good the Checkerboarding technique is.
It is not to say that Checkerboarding technique is the best way to go, but it depends on the developer that how they choose to implement it. If implemented carefully then the difference is very hard to spot.
Furthermore, implementing these techniques is not so difficult as Sony itself provides the reference code for these techniques. Also, Checkerboarding can be implemented in a game in a matter of days by a single programmer if Mark Cerny is to be believed.
The bottom line is, Checkerboarding is an extremely effective technique if implemented carefully and given that it does not even take much time the developers almost have no excuse for not taking advantage of PS4 Pro’s upgraded hardware.
Given that PS4 Pro is not even a next generational leap but an upgraded version of a standard PS4, we are hopeful that the next console from Sony, presumably PS5, will be able to run games at native 4K like what Microsoft is aiming for its Project Scorpio.