It's the PlayStation 4 Pro demo many hoped to see - but never came to pass. This is Uncharted 4 running at 60 frames per second, and it looks sensational. Sony's new console is built from the ground up principally to run PS4 engines at higher resolutions with similar performance levels to base hardware, but many hoped to see game developers take a different approach. As things stand, the video on this page stands apart as a kind of 'what if', the path not taken, if you will. What if PS4 Pro's 2.3x GPU boost could be used to double Uncharted 4 frame-rate instead of targeting 4K displays?
Before we go any further, it's important to emphasise that, strictly speaking, this demo wasn't captured in real-time and didn't require any kind of access to PlayStation 4 Pro hardware - it's actually derived from footage taken from the standard console running the retail version of the title. As you progress through the game, players have the opportunity to buy 'cheats' and bonuses - one of which is a slow-motion mode. This maintains the game's 30fps frame-rate, but slows the action down.
The captured video is then sped up to 200 per cent, nullifying the slow-motion effect and translating the 30fps update to 60fps. It's a really neat trick and as much as we'd like to take credit for the idea, the technique was first utilised by NeoGAF user Kanuuna, who contacted us a few days back and showed us his proof of concept video showing the Madagascar stage, that you can watch here - yes, more Uncharted 4 60fps footage! Compromises here are two-fold - first of all, audio can't be reconstructed without a metallic echo and secondly, the game itself isn't running at 50 per cent speed in slow-mo mode. It's actually a touch more spritely, so while the 200 per cent speed boost gives us the frame-rate we need, it also gives the impression of the game running faster than it actually does in standard gameplay. Uncharted 4 Turbo Edition, any one?
However, the enhancements to the experience running this title at 60fps are clear to see. It looks simply phenomenal - and in particular, the physics work during the set-pieces looks absolutely breathtaking. As a taster of how this cutting-edge title could look at 1080p60, the appeal is undoubted - and one can only imagine how different the reaction to PS4 Pro would have been if this were demonstrated last week.
As things stand, Naughty Dog chose to go down a different path based on what we saw at the PlayStation Meeting. In common with all of the Sony first party demos, the Uncharted 4 PS4 Pro demo operates at a much higher resolution than 1080p (Naughty Dog's Arne Meyer wouldn't talk specifics on-site) and it utilises HDR. However, performance is unchanged at the game's standard 30fps target. Whether a higher frame-rate mode will make it into the final game remains to be seen, but we suspect that Naughty Dog has its hands full optimising for just the one PS4 Pro target.
So in the wake of this remarkable footage, the question is really why PS4 Pro can't be a 1080p60 box, bearing in mind the huge increase in GPU resources. Well, what's clear is that PS4's base hardware design has a clear GPU power skew as opposed to its CPU provision - and that is even more unbalanced in PlayStation 4 Pro. Graphics capabilities are up 130 per cent, but the AMD CPU cluster only sees a 30 per cent uplift. Doubling up raw throughput could well push the CPU component beyond its limits.
And this may well explain the mooted performance levels of the various PlayStation 4 Pro modes built into the upcoming port of Rise of the Tomb Raider. There's a 4K optimised mode, a maxed-out 1080p30 preset but also the ability to run the game with an unlocked frame-rate, said to produce results in the 40-60fps range. Bearing in mind that the 4K mode looks rather nice, the notion of a 1080p mode not hitting 60fps seems hard to believe - unless there is a non-graphics bottleneck, of course.
By settling on a higher resolution alone, the task of bringing Uncharted 4 to PS4 Pro becomes a lot more manageable - the base game logic remains as is, and the GPU is put to use in handling a much higher pixel-count. In the case of a title like Uncharted 4 - a legacy game revisited for PS4 Pro hardware - there may also an engineering resource issue too.
Opting for a higher resolution and the same performance levels simply requires less engineering effort as opposed to a widescale optimisation effort in pushing for 60fps. We're unsure how many staff Naughty Dog has working on updating Uncharted 4 and The Last of Us for PlayStation 4 Pro, but we do know that Sucker Punch has just two team members doing the equivalent work for InFamous Second Son and First Light. In these early days, it's all about making as much from the work that's already been done as opposed to sinking lots of effort into further optimising a perfectly good engine.
It'll be interesting to see the various routes taken by developers as they get to grips with the PlayStation 4 Pro hardware but certainly to begin with, everything we've seen so far points to Pro features being supplementary to the base PS4 experience. Owners of existing hardware who don't possess 4K HDR display technology may not actually miss out on much in many cases, aside from some impressive super-sampling effects. Increased visual fidelity at 1080p remains an option though - and a route that Epic is confirmed to be pursuing with Paragon.
Of course, the utilisation of Pro hardware may vary on a title by title basis and the overall outlook on how the hardware is utilised may change across the months as developers get to grips with the new kit. It certainly adds a new dimension to our face-off coverage that we look forward to implementing come November.