UPDATE 27/2/17 8:45am: Patch 1.02 has dropped for Horizon Zero Dawn, delivering a small range of changes and updates. However, for PS4 Pro owners, the ability to choose two rendering modes is now available with users able to favour performance or resolution. Prior implementations of performance modes in the likes of Knack, Rise of the Tomb Raider and the inFamous titles have seen developers unlock the frame-rate, leading to a much faster, but often more jerky experience. On both counts, this does not happen in Horizon Zero Dawn, which opts for smoother performance instead.
Resolution is pegged to 1080p when you enable the 'favour performance' mode, but instead of letting the frame-rate run as fast as it possibly can, Horizon opts to use GPU power to more closely lock to the target 30fps instead. It's an interesting idea, but fundamentally not that much of a game-changer - simply because Guerrilla's performance at 4K is already so good with only very minor drops (if any) in most areas.
For 1080p users, effectively you're offered a small bump to performance but only very rarely, at the expense of losing excellent SSAA coverage. Meanwhile for 4K display users, you're trading one of the very best ultra HD presentations available on PS4 Pro for the same minor increase in game fluidity. It's an interesting option to have, but we'll be sticking with the default profile that favours 4K resolution.
Original story: When the first PlayStation 4 Pro leaks appeared, many were concerned about what the arrival of the new hardware would mean for the platform as a whole. Would developers target one system over the other? Would the older hardware get left behind? Horizon Zero Dawn is a highly important title - developer Guerrilla Games has a reputation for remarkable technical innovation and accomplishment. The team would be expected to deliver a title that showcases the power of PS4 Pro, while at the same time demonstrating that there's plenty of life in base hardware. Based on a week with the game, the developer has delivered on both counts. Horizon is a stunning technical showcase, no matter which iteration of PlayStation hardware you own.
If we look back at the reveal of PS4 Pro at last September's PlayStation Meeting, we were promised a system that delivers enhanced graphics, higher performance and a 4K presentation. Back then, the demo we saw certainly delivered on the latter, at least. Horizon's implementation of checkerboard 4K was simply stunning - perhaps a touch softer than native rendering, but beautiful nonetheless. Alongside Sony Bend's Days Gone, it was the showcase for the Pro's 4K capabilities. However, the demo was clearly early - as borne out by a work-in-progress performance analysis, which showed frequent frame-rate drops beneath the target 30fps.
The final game sees the vast majority of these issues resolved, with the vast majority of gameplay operating at a locked, properly frame-paced 30fps. It's the scalability of the Decima engine between PS4 and PS4 Pro that proves fascinating though - both versions still exhibit very minor instances of dropped frames (barely noticeable for the most part and masked by motion blur when they do appear) and these very minor drops are essentially mirrored between both platforms, with a very small improvement on PS4 Pro. It seems that extensive particle work and alpha effects cause the drops - as infrequent as they are.
Also important is the consistency of performance during traversal in the open world. Producing a sandbox game of this scale is not an insignificant task - many similar titles struggle to maintain solid performance during traversal as the CPU needs to stream in and decompress open world data on the fly, while continuing to process game logic and prepare instructions for the GPU. It's for this reason that titles like Fallout 4 and Just Cause 3 can hitch and stutter when the player does nothing more than move from A to B through the environment. Crucially, Horizon Zero Dawn is immune to this issue - making your way through the open world is a super-smooth experience regardless of the PlayStation hardware you're using.
Horizon's excellent performance at checkerboard 4K vs the native 1080p of the base PS4 version is a great achievement. While the Pro hardware has 2.3x the GPU power of the standard model, memory bandwidth hasn't scaled in step - and it's rare that we see a PS4 engine scale so gracefully between 1080p on base hardware and 4K on Pro (checkerboard or otherwise). That Guerrilla has achieved this with no impact to performance is impressive enough, but the team has pushed the envelope here, handing in more visual enhancements over the base version of the game.
While Horizon would be lauded for its resolution boost alone, what we like about the title's presentation is that Guerrilla has accepted that it's not just the pixel-count alone that matters - more is required to deliver a great 4K presentation. With that in mind, we were really happy to see improvements to resolution on some textures. Also worthy of praise is a marked increase in texture filtering quality. Lower levels of anisotropic filtering on base hardware can stand out on a 1080p image - but the effect is much more pronounced at 4K. Thankfully this is not an issue with Horizon.
We're still working on our main Horizon Zero Dawn coverage (expect much more later in the week), but it's worth pointing out that even this performance analysis article needs further work in order to be considered complete and final. Late last week, Sony revealed that an upcoming 'day zero' patch - which is not yet available to press - will allow Pro users to choose between the checkerboard 4K mode, or else a new performance-orientated option.
This new mode redirects Pro power towards a higher frame-rate - exactly the kind of thing we've seen on the inFamous and Rise of the Tomb Raider PS4 Pro updates. There's no promise of 60fps in the Sony notes - merely mention of smoother frame-rates - so we will report back on what the performance mode actually delivers as soon as we can. However, we can confirm that the patch will available by the time the game launches.
The ability to choose between resolution and higher performance may well be the icing on the cake, on what is already a technologically outstanding title. However, even without the new mode, the combination of brilliant art design, great performance and a sublime 4K presentation make this the most impressive PlayStation 4 Pro title we've seen so far. But at the same time, it's clear that base hardware hasn't been left behind - Horizon is an equally impressive achievement for the standard PS4 too.