GT Sport on PS4 Pro: 4K impresses, but what about 1080p support?
UPDATE: Enhanced MSAA as well as higher frame-rates confirmed for full HD users.
UPDATE 25/5/17 1:00pm: Sony has been in touch to point out additional 1080p features in Gran Turismo Sport for PS4 Pro users, specifically that along with the significantly improved in-game frame-rate and unlocked replay performance we've highlighted in the 1080p comparison further down this page, anti-aliasing is also enhanced with the inclusion of 8x multi-sampling (MSAA).
This does change the conversation, as 1080p with 8x MSAA would be a fascinating comparison point with an 1800p checkerboard presentation downscaled to full HD resolution - conceivably, the presentation could be cleaner. Polyphony has done something similar before with its lower resolution modes of course, with improved MSAA present on the 720p mode of Gran Turismo 5.
It's an aspect we should have picked up on and apologise for missing, because reviewing further media does show the difference - though in fairness, the MSAA coverage does seem a touch inconsistent and the effect overall is subtle. Polyphony Digital has supplied a brace of shots here (the first two in the sequence), and we've supplemented that with a few of our own shots.
Original story: Three years into the current console generation, legendary developer Polyphony Digital is almost ready to unleash its first PlayStation 4 title - Gran Turismo Sport. We've been spending time with the beta version of the game recently and we're happy to report a big leap in fidelity over the series' PS3 audio-visuals: there's a radical revamp in terms of materials, detail, lighting quality and engine acoustics. We'll have a more in-depth analysis of this later, but the beta also gives us our first opportunity to see how Polyphony is making use of the additional power offered by PlayStation 4 Pro.
Series creator Kazunori Yamauchi gave us the headline facts and figures for Pro support back in March, revealing an impressive spec for users with 4K screens: rendering resolution is set to 1800p, achieved using checkerboard upscaling. The bt.2020 colour space is utilised along with HDR rendering, with Yamauchi telling journalists that this allows Ferrari red to be accurately represented in a video game for the first time.
GT Sport's HDR support is also exemplary - with support for displays operating up to 10,000 nits, effectively ensuring that the high dynamic range rendering is future-proofed for the much more capable HDR TVs to come. The GT Sport beta offers up an HDR brightness slider for tweaking to your individual display, and even on less capable mid-range HDR screens, the effect is impressive.
Our own pixel counts confirm both the 1800p resolution, plus the checkerboarding upscale effect. You don't get the pristine 1:1 pixel mapping found from a native 4K output, but as the video on this page demonstrates, the overall effect is excellent and certainly a huge upgrade from the standard, base 1080p mode. It's another example of how clever rendering techniques are allowing the Pro GPU to effectively punch above its weight, and it's good to see decent support for 4K displays here, when too many Pro titles are lurking in 1440p territory - if there is support for the new console at all (Prey and Shadow Warrior 2 are two recent releases with no Pro features whatsoever).
But what Yamauchi didn't share is how Gran Turismo Sport aims to support PlayStation 4 Pro users with their consoles attached to standard 1080p displays - and there's both good news and bad news here. To address the key negative point first, Polyphony Digital joins the ranks of developers that have decided not to support 4K downsampling for 1080p users. In fact, stacking up the beta's visuals on both base and Pro hardware, we could find no visual improvement whatsoever between the two consoles. It's disappointing because on a technical level, there is no reason whatsoever why this feature cannot be implemented.
This is proven very easily. If you have an ultra HD screen, you can boot the game with 4K display output active, then jump back to the front-end, select 1080p and gameplay continues as normal with system-level super-sampling engaged. However, if you only own a 1080p screen, there's no way to access the 4K output to begin with - unless you buy an expensive 4K downscaler like HDFury's HDLinker. That's why we need the developer to provide an in-game toggle, or at the very least an option to choose which Pro implementation to use when the game boots.
But that's not to say that 1080p users are left with no enhancements whatsoever, which brings us onto the good news. While GT Sport's 1080p output on Pro is identical to base hardware, the extra horsepower is put to use - Polyphony directs that 2.3x increase in GPU power towards improved performance. In like-for-like tests, we found that the PS4 Pro version held a virtually solid 60fps lock, whereas base hardware can drop to the mid-40s in the most densely packed race scenes. This is a welcome enhancement - dropped frames means a disconnect in terms of controller response, plus intrusive visual judder. Based on what we've played in the GT Sport beta (which, we should stress, is only a sampler of the full content line-up), playing on Pro keeps you at 60fps with only the most minor, essentially unnoticeable drops.
The improvements extend beyond gameplay too. Since the Gran Turismo series moved onto PlayStation 3, Polyphony has opted for 30fps replays, halving frame-rate in order to layer on additional effects and deploy higher detail models. This remains the case for Pro users running the 4K mode, and for base PS4 hardware operating at 1080p. However, Polyphony unlocks the frame-rate with Pro at full HD, meaning you get the full package of additional replay visual enhancements, and a (mostly) 60Hz output. Frame-rate only drops when many cars are on-screen simultaneously. In this respect, the performance profile in these unlocked replays is similar to base PS4 gameplay.
The return of 60fps replays is welcome, as is the ability to power past most of the performance issues found on base PlayStation 4 hardware - though in the latter case, we had harboured hopes that Polyphony might use the power of a new console generation to match the rock-solid 1080p60 lock seen in the Forza Motorsport series, even on base hardware. At least the option to get there - bar one or two dropped frames - is there with PlayStation 4 Pro, and it clearly has gameplay benefits.
But the question is why Polyphony would automatically assume that Pro owners with 4K screens wouldn't want access to the option of improved performance. Users with ultra HD displays need to reset the front menu to 1080p, boot the game then return to the front-end menu to reset the display output to 4K (not doing so may incur additional display latency as it carries out the scaling task instead). Based on the beta code at least, this is the only way to access the performance mode if you don't have a full HD display. Again, a simple in-game toggle would solve this issue completely.
That said, while the 4K mode can drop frames, it's still an improvement over the performance seen in the last-gen Gran Turismo titles - it's far from perfect, but it's still impressive based on the sub-set of content we've had access to, and indeed the limited time available for testing (curiously, multiplayer racing in the beta is only available during certain times of the day). And with that decent performance profile in mind, completely locking out the option of 1080p super-sampling for those without 4K screens is a disappointment. Quite why developers are persisting in locking away specific modes for specific displays when the feedback from users is crystal clear remains baffling. We hope that Microsoft's decision to support all output modes for all screens with Project Scorpio will bring about positive change for PS4 Pro users.
Overall though, based on what we've played so far in the GT Sport beta, Pro users are well looked after overall with two different gaming profiles that both provide an improved experience compared to what's on offer from the base PlayStation 4. There is some controversy about Polyphony's approach overall - that perhaps the visual aesthetic isn't enough far enough removed from Gran Turismo 6. We'll have a deeper look at that soon, but right now, having revisited GT6, we're fairly confident in saying that a significant array of big improvements all contribute in providing a notable generational leap. What we've sampled from the beta so far is impressive, and we're really looking forward to playing the final release.