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Sony’s PlayStation NEO is set to debut sometime this year, if rumors are to be believed. Not only do these rumors put the launch at around the time of the PlayStation VR launch as well (13 October 2016), but they also keep on wildly guessing at the system specifications and the system’s capabilities. Well, to add fuel to the fire, what appears to be an official Sony document meant to be seen by developers and studio partners only has made its way to the public. It looks like this is the same document that leaked to some select websites a few months ago (both Neo and I wrote about those rumors at the time, too, with both of us offering different perspectives).

Now that we have what seems to be the original document out in the wild, courtesy of a WCCF leak, it’s time for some analysis. Keep in mind that whatever you see in the following slides may have already changed in the months following the leak and the reveal of Project Scorpio from Microsoft..

Possible launch window: October 2016

Sony PS4 NEO developer slide leak (11)

Giving credence to the idea that the NEO is launching this year, and soon, is this slide which basically tells developers to be ready for the NEO by October 2016. However, the wording is a bit strange, and I think that it’s possible that something is getting lost in translation. The slide basically outlines that if you’re submitting a game for compatibility testing with the NEO that was designed for the PS4, any games submitted before 30 September 2016 need to have a day one patch available to make sure that if someone runs it on a NEO console, that it won’t glitch and bug out on the more powerful system.

Additionally, if you’re submitting something after the start of October 2016, your game at minimum needs to have a NEO mode where things like the graphical fidelity is increased, which includes the use of higher resolution textures and a faster framerate. This is interesting for two reasons: one, that Sony isn’t mandating that all developers include anything for the NEO for games already out in the market. All you need to do is submit a patch for it to be fed to the system on launch day if you play that game.

Two, developers aren’t being forced to add in NEO modes for older games or games already in development, but they are required to do it for any new games submitted after October 2016. This tells me that the NEO isn’t being launched in October 2016, but possibly much later in the year.

Sony PS4 NEO developer slide leak (10)

A section of another slide details the prototype returns. Sony has had these out for a while already (possibly as early as April this year) and those will eventually be returned to be replaced with developer kits or functional retail consoles for developers to test their games on. “Release timing is still TBD” tells me that when Sony made these slides, they had no idea about the Project Scorpio time frame, which is set for a launch in late 2017. They have about 18 months to pick and choose when they want to launch, and all indications are that they’re ready, but it looks like they’re waiting for something.

Hardware changes galore

The hardware specs don’t change too much. At a minimum, games have the same access to the same amount of cores and system memory as the base PS4 model. Hardware-wise, it looks like the initial rumors were true, although this could all have changed by now. AMD will be supplying Sony with higher-clocked Jaguar-based processors at 2.1GHz, which adds up to a 30% performance boost. On the GPU side of things, there’s a doubling of execution units and a clock speed increase, pushing up the total compute rating to around 4 TFLOPS.

The only thing I’m not certain about is the hard drive speed. If the specs for the storage remain unchanged, then we’re limited to SATA 2 speeds of 300MB/s. While no hard drive can ever hope to reach those speeds in a 2.5-inch form factor, I would have liked to see changes in the storage subsystem to the extent that adding in a SSD to the PS4 NEO would yield increased system performance and shorter game loading times.

Interestingly, there’s a requirement for GPU utilisation that I’ve never seen before – that games reserve 50% of the GPU power for the background execution queue, but also spend no more than 0.5 milliseconds on foreground execution, which involves starting to executing code required for a new frame. That code needs to be executed in 0.5ms or less in order to not put backwards pressure on the display pipeline, because as soon as one process takes more than 0.5ms to complete, it’s moved into the background execution queue. Delays in code being completed may lead to a frame arriving later to the display than intended.

With the frame time target for a 30fps game being 33 milliseconds per frame (16.6ms for 60fps), developers have to finely balance how much stuff they’re trying to do on a per-scene, per-frame basis, while still utilising all of the power the PS4 provides. If none of the code running at that time fits into the foreground execution queue, then that’s 0.5ms wasted. Hence, developers are drawn to running as much code as they can in parallel, and this is why GPGPU compute is so useful in the case of the PS4 and Xbox One – the GCN architecture inside the GPU lends itself better to parallel computing and is a wide engine that would otherwise have resources sitting idle. The more stuff they can cram into that 0.5ms gap in parallel, the better the game will run.

It’s not a new feature, admittedly, but it’s fun to know how these things work, and the tight schedules they run on. Also, 1080p video captures are on the cards. Woohoo!

How to do 4K on a console

Now we get to the interesting part – how to run 4K on a console not built for it especially. Because here’s the catch – NVIDIA’s latest mid-range GPU, the GeForce GTX 1070, is just about on the spot for running games at 4K and being able to hit a 30fps minimum frame rate. You’d have to reduce visuals for some games to hit that spot, but it’s possible that most games will run at their highest settings on that card. The PS4 has much less available VRAM and a much lower TDP to work with, so it’s effectively only working with around half the power of a GTX 1070. That means there will have to be serious compromises to get games running fluidly on 4K displays.

Sony’s looking at this problem and offering several solutions. The first is obviously upscaling from 1080p to 4K, with all the visual display issues that may entail. Some games will do this for performance reasons and the developers will have to implement higher levels of anti-aliasing to get rid of jagged lines and avoid the shimmering effects seen on Xbox One games which already do the same thing.

The second option is running the game at 4K anyway, and scaling down to 1080p. This is the best one out of the four if your game hits all its performance targets, because people on 1080p displays benefit from it. The images look twice as sharp compared to regular 1080p output, and the developer might get to use lower levels of AA to reduce the load on the GPU. Win-win all around, it seems, though things are never this easy.

A third option is to run the game at a resolution higher than 1080p, but lower than 4K to increase performance, and Sony offers a number of framebuffer resolutions that developers can use. Since this was already a feature for the PS3 for many years, and because it results in the least amount of headache for developers, most might opt for this route and upscaling. Performance is improved as a result, and gamers get super sampled 1080p output regardless.

The fourth option is checkerboard rendering, where the frame is divided up into squares like a checkerboard and then rendered individually. This is less work than producing an entire frame first and then doing things to it, as the samples are smaller than a full frame, and actions like performing anti-aliasing costs very little in terms of GPU power because of the sample size. The actual methods for implementing checkerboard rendering are very complex and too long to discuss here, but you can check out these slides from GDC 2016 where Ubisoft Montreal’s Jalal El Mansouri discussed how his team approached the challenge of rendering Tom Clancy’s Rainbow Six: Siege on consoles. 

Finishing Up

Sony PS4 NEO developer slide leak (1)

It’s quite clear that Sony has been thinking about this for a while. Not only is the NEO built to be capable of running games on 4K displays, it’s also going to be quite good at 1080p gaming, though oddly Sony isn’t willing to let it become a replacement for the base PS4. They’re not going to, for example, allow most developers to upscale from 1080p to allow a game to run at 60fps – they’d much rather everyone implement a fine balance between performance and image quality, rather than brute force their way through with something that looks bad.

Seeing these slides for myself, I’m a little more interested in the NEO and what it has to offer, and a little less apprehensive about how it’s going to split the ecosystem. It seems that Sony has gone out of its way to create rules for developers to avoid this issue entirely, and there is a small benefit to using a NEO on a 1080p display even though Sony promised it to no-one – quite a lot of games will offer a super sampled 1080p image that looks hawt. I like the sound of that. We don’t know everything there is to know about the NEO, but from a hardware standpoint on paper, it’s shaping up to be a great system.

Roll on holiday 2016!

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