How Xbox One S is falling behind - but also defining the future

[Hossam Taibi]

What does the future hold for the Xbox One S? At Digital Foundry, we've noted something of a concerning trend for Microsoft's base console - while system exclusives continue to hold up well from a quality perspective, top-end third-party titles are pushing the system to its limits - with sometimes disappointing results. The question is this: if the S is losing pace with the competition, how well can it hold up in the years to come? After all, its successor is not likely to arrive until 2020.

Let's put all of this into context. The Xbox One has always had a less capable GPU than the PlayStation 4, so the generation has typically seen the PS4 deliver resolution or frame-rate advantages over its Microsoft counterpart - this is nothing new, and the 1080p/900p divide has been in place for much of the generation. By and large, 720p vs 1080p comparisons aside, the differences only really become evident if compared both consoles directly side - so what's changed?

There's a combination of factors in play here, but mostly, I suspect it's down to several factors - firstly, the fact is that the vanilla PlayStation 4 is effectively the base platform owing to its ginormous installed userbase. Secondly, developers are pushing that platform harder than they ever have before - so compromises in resolution in favour of features on a PS4 build have a more profound impact for the Xbox One S build. Then there's the arrival of Xbox One X - in terms of its basic nuts and bolts design, its architecture has a crucial commonality with PS4 and Pro, something the S doesn't have - a fully unified memory structure.

Across the entire console generation, we've heard complaints from developers about the base Xbox One's ESRAM - not so much the concept of a high bandwidth section of memory that's faster than the rest, but more the fact that there's only 32MB of it. If render targets can't fit into the space, they are relegated to much slower DDR3 with a profound drop in performance. In effect then, developing for the Xbox One S has more fundamental challenges then - the GPU is less capable, and the memory set-up is much more challenging to work with. Meanwhile, Xbox One X shelves ESRAM completely and follows the completely unified memory set-up used in the PlayStation consoles.

So how has all of this impacted actual software? DICE's Battlefield 5 is a good example, pushing technology with cutting edge features, but paying for it by reducing resolution dynamically and using reconstruction techniques in an attempt to restore image quality. It's not a totally ideal situation for image clarity but it passes muster on PlayStation 4, but looks significantly blurrier on Xbox One. Reconstruction to hit 720p in the most intense scenes? It works, frame-rate is kept high, but it's not pretty.

Red Dead Redemption 2 is another example. Remarkably - bearing in mind how advanced this game is - it's feature-complete alongside the three accompanying console builds. Not only that, but it's effectively delivering the same performance level as the PS4 game. However, the temporal anti-aliasing techniques combined with an 864p base resolution again deliver a very blurry presentation. It's not particularly flattering on a living room flat panel, and scales even more poorly on the latest 4K displays. Temporal AA has become something of a standard at the tail-end of this generation and it can look great, but it does rely on a decent base resolution.

Another interesting scenario is presented by Avalanche's Just Cause 4. In the wake of poor performance in JC3, the developer tackled the challenge offered by its huge explosions and insane physics work by optimising CPU utilisation and - yes - fully embracing dynamic resolution scaling. The vanilla PlayStation 4 is pushed hard and bottoms out at a 720p pixel-count - so where does leave the Xbox One S? A blurrier image more of the time, combined with frequent drops to the target frame-rate.

We also spent some time with the Codemasters Evo team last year as they closed in on the final days of development for its debut title, the criminally overlooked Onrush. It's another example of a cutting edge engine built from the ground up, fully dynamic in almost all regards. It also offers users the chance to choose between resolution or performance, and plays best at 60fps. However, this option wasn't available for the base Xbox One version of the game, which only featured a 30fps mode.

All of which sums up our concerns about the trajectory of the Xbox One S - with two more years projected for the current console generation and the PlayStation 4 userbase likely to hit 100m well before that, it's Sony that defines the technological baseline. As the vanilla PS4 gets pushed ever harder, the worry is that the Xbox One will struggle still further.

From a marketing perspective, Microsoft is insulated somewhat, simply by virtue of the Xbox One X's existence. So, for example, it's interesting to note that the firm highlighted our coverage of Red Dead Redemption 2. We said that the game looks and runs best on Xbox One X, and it does - indeed, for that level of technical accomplishment to render natively at 'true' 4K is an astonishing achievement. But we also discussed how blurry the S version looks and how it doesn't match up to the others. If the X wasn't about, the story wouldn't have been anything like as positive for Microsoft.

Obviously though, the Xbox One S isn't going anywhere, and it's highly likely that the machine will take on a new role. The X is there for the core gamer who values good performance and image quality worthy of their 4K screen, but Microsoft is planning on expanding its audience and it's here where the S plays a crucial role. The firm has already revealed that its cloud-based streaming system - dubbed Project xCloud - features server blades built around the S architecture. Bearing in mind that mobile devices are the primary target for streaming, resolution deficiencies won't be an issue, while using S hardware instead of X represents huge power savings and far greater efficiency. It's a more obvious fit for the task in hand.