Tech Analysis: Can The PS4 Pro Deliver ‘Native’ 4K In Modern Games?

Native 4K on the PS4 Pro may be possible with games build on outdated frameworks, but what about software that uses modern technology?

Posted By | On 13th, Sep. 2016 Under Article, Graphics Analysis

Sony’s console hardware plans have been, well, leaky, to say the least. We’ve known about the existence of a mid-cycle console refresh from Sony for the past several months, at least as far back as the massive Eurogamer leak on what was called the PlayStation Neo. Sony scheduled a conference on September 7th to talk about new hardware. The PlayStation 4 Pro wasn’t a surprise to anyone (although the name was: Pro, really? That’s swiping about the only original thing Apple’s done in recent times, which is to rename their high-end iPad SKUs.) Quite honestly, we like the sound of “PS4 Neo” a lot more than PlayStation 4 Pro–isn’t “professional” uh the very antithesis of leisure? But semantic quibbles aside, the PlayStation 4 Pro is here to stay. More significant is Sony’s 4K push with the PlayStation 4 Pro.

Earlier reports about the “Neo,” seemed to indicate that Sony had largely conceded the 4K console space to Microsoft, focusing instead on delivering a platform for richer 1080p experiences at higher framerates. However, with the PS4 Pro announcement, it seems that Sony’s angling towards Microsoft’s Scorpio pitch: largely identical visuals and framerate, just at higher resolutions. The question here, though, is whether the PlayStation 4 Pro, with its relatively modest 4.2 Teraflop GPU can hand in native 4K experiences.

The short answer? It can’t, at least apart from graphically unintensive titles or last gen/remastered titles like The Last of UsWe run a 980 Ti here that’s quite a bit more powerful than either Pro’s GPU or the upcoming Scorpio’s, and playable 4K gaming remains a challenge. Considering that the Polaris architecture uses more or less the same GCN cores we’ve seen in AMD parts since 2012, it becomes fairly straightforward to directly  compare the PlayStation 4 Pro’s specs with an equivalent PC build–teraflops do equal teraflops here as long as everyone’s on the same GCN boat. Before we proceed further, let’s quickly list out the Playstation 4 Pro’s key tech specs:

  • Processor: Eight-core processor at 2.1 GHz, on the Jaguar Architecture
  • GPU: Polaris 10-based GPU with 2304 shader cores, running at 911 MHz, offering 4.2 TFlops of compute power
  • RAM: 8 GB of GDDR5 RAM, with 216 GB/S of memory bandwidth

While the custom, eight-core Jaguar processor doesn’t quite have a clear parallel on the PC side of things, we’d expect performance–with perfect CPU scaling–to roughly double the Athlon 5370, which is a quad-core Jaguar part that operates at 2.2 GHz. In absolute terms, that’s a bit more CPU power than a Haswell i3. But, considering that current game engines continue to favour high IPC over multiple cores, the PS4 Pro’s CPU performance would more likely be in the vicinity of the FX-6300, which substantially bottlenecks PC games at framerates higher than 30 FPS.

While it’s debatable as to just how much low-level console optimizations can tilt the scales, CPU bottlenecking in PS4 titles offers ample evidence that the Jaguar-based processor seen here can and will hold back a relatively powerful GPU. With even Core i5’s suffering from stark CPU-bound framerate scaling in games like Fallout 4, we’d need something in the vicinity of a 100-150 percent increase in CPU power for bottlenecking to not be an issue. Considering power and thermal budgets, the only way this can be achieved is by deploying a newer, higher IPC architecture like Zen. As such, Sony’s decision to stick with Jaguar has a significant impact on the PlayStation 4 Pro’s 4K-readiness.

Current 60-FPS titles like Call of Duty: Black Ops III were clearly designed with the consoles’ CPU-side limitations in mind. As a result, the 4K treatment in these cases is more a factor of GPU power. In line with Activision’s presentation, we expect upscaled (not native) 4K Call of Duty titles to hit 60 FPS on the PlayStation 4 Pro. We’ll talk more about upscaling in the GPU section up next.  As for lighter titles like Overwatch, a native 4K/60 experience isn’t outside the realm of possibility. When it comes to more intensive titles–the kind that hit 1080p and 900p at 30 FPS on the PS4, the impact of CPU bottlenecking is less straightforward. The PS4 Pro’s GPU is fairly powerful, but, with even the Pascal Titan X struggling to deliver a 4K/60 FPS experience with all the bells and whistles, most PS4 Pro titles will likely continue to run at 30 FPS. Even in CPU-bound scenarios, this isn’t a particularly target to reach.

Ironically, where CPU  bottlenecking may have prevented a game from exceeding its 30 FPS cap at 1080p, GPU bottlenecking could very well enforce that cap when the Pro runs at higher resolutions. Because the PS4 Pro’s GPU isn’t quite powerful enough to hand in 4K/60 FPS experiences, a locked 30 FPS update would ameliorate the CPU bottlenecking issue. CPU bottlenecking generally causes minimum framerates to plummet in CPU-bound scenarios, such as the Corvega Assemply Plant in Fallout 4, where the PS4 hands in a sub-30 FPS update. As the Xbox One S–which featured a modestly upgraded GPU with no CPU increment–went to show, a faster GPU isn’t going to do much for  you in CPU-bound scenarios. As far as CPU bottlenecking is concerned, we believe the PS4 Pro will hand in broadly the same kind of experience as the PS4 with 30 FPS titles.

The PS4 Pro’s GPU upgrade is the singe most significant aspect. Based on the Polaris 10 GPU–the very same as the one powering the RX 480–the PS4 Pro’s GPU is more than twice as fast as its PS4 counterpart. The question of whether or not the PS4 Pro can do 4K gaming rests squarely on its GPU power. Because AMD carries forward its years-old GCN architecture with Polaris, it becomes possible to do an apples-to-apples comparison of the PS4’s GPU to equivalent PC hardware. Unfortunately, conservative power budgeting means that the RX 480 isn’t the reference point here: The PS4 Pro runs its GPU at a much more conservative 911 MHz as compared to the 1266 MHz boost clock for the reference RX 480.

As a result, we’re looking at 30 percent lower performance, and at 4.2 Teraflops, that makes it just a hair faster than the 3.97 Teraflop R9 380X. Now, the 380X remains a fair option for 1080p gaming: drop down to console-equivalent settings, and you’ll be chasing 1080p/60 FPS in many cases. AMD also promotes the card as an entry-level option for 1440p gaming–in reality, this means toning down settings and making do with a 30 FPS lock. But in no way is the 380X a suitable card for 4K gaming in anything apart from the least intensive titles. So the 380X is a great performer at 1080p, and hands in a solid experience at 1440p. This puts it right in line with what we can expect of the PS4 Pro’s performance profile. But then why would Sony be targeting 4K gaming at all?

This is where Sony’s innovative “checkerboard” upscaling technique comes into play. We’ve seen the use of temporal reconstruction techniques in multiplats in the past, notably in Rainbow Six: Siege, and Quantum Break.  Essentially what’s being done here is that a lower resolution framebuffer is used (at 1280x720 in the case of Quantum Break on Xbox One). Frame data from multiple frames is extrapolated to increased perceived detail, and hardware AA is deployed to take care of aliasing. While the end result is noticeably softer than a native 1080p presentation, it offers objectively better image quality than a straight-up upscale. With the PlayStation 4 Pro, developers will make use of the 2x2 checkerboard technique, which obtains a 4×4 grid of pixels from a 2×2 grid of rendered pixels.

In order to output 4K, 2×2 checkerboard will utilise a 2688×1512 framebuffer, just a hair more than 1440p, which is the 30 FPS sweet spot for the PS4 Pro’s graphics component. The folks over at Digital Foundry spent some quality time with the PlayStation Pro 4, specifically with a build of Horizon Zero Dawn, operating at upscaled 4K.  One thing that piqued our interested was how Richard Leadbetter described the subjective image quality–while it was a definite step up from 1080p, it was “softer” than the native 4K presentation that a high end PC can output. This brings us to an interesting point, something we’ve noticed personally having fiddled with upscaling quite a bit to get a suitably playable experience on our 4K TV. The first point here is that upscaling quality has a lot to do with the quality of the upscaler. We have a budget 4K set, a 55-incher from Vu. The TV’s built-in upscaler producers horrifying results when upscaling 1080p content–1080p games upscaled to 4K look worse than SD quality video footage.

On the other hand, Nvidia’s GPU scaling option is near-transformative–1080p output in games like Dark Souls 3 looks a little softer than native 4K, with a bit more aliasing to deal with, but that’s about it. And 1440p upscaled to 4K looks even better, to the point that we’d have likely used that option for every game if it weren’t for the annoying fact that our TV only supports 60 Hz output at 1080p and 4K, but not in between. Our experience with seems to indicate that even plain old upscaling–none of that fancy checkerboard stuff–offers noticeably better image quality on a 4K panel, when upscaling from 1440p.

At the end of the day, irrespective of the post-process tricks you may or may not use, less pixel data means less pixel data. While we’ve yet to see the PS4 Pro’s reconstruction technique in action, we’ll not be setting our expectations too high at this point, considering the results we’ve already gotten used to seeing with standard upscaling from a 1440p source to 4K. What’s important to note here, though is that developers have been given quite a bit of leeway in terms of what they wish to accomplish in terms of resolution/framerate on the PS4 Pro. The only hard requirement is that games need to be running at at least 1080p. While a lot of 4K and upscaled titles were showcased at the September 7th event and later, the fact remains that the vast majority of people still have 1080p monitors/TVs, meaning that that is also where much of Sony’s market is.

What does this extra GPU power mean for people gaming at 1080p? Higher quality geometry, longer view distances, and more advanced visual techniques (like contact-hardening shadows) could make the Pro a viable proposition for people without 4K TVs, but, again, it’s up to developers to decide whether or not to deploy additional features.

The most likely scenario we see here is that PS4 Pro owners at 1080p will benefit from downsampling, which is running at higher than native resolutions and then scaling back down to comprehensively tackle aliasing. Just how much of a discernable impact this will make remains to be seen. Unlike MSAA, downsampling handles aliasing on everything, and that includes transparencies like fences and hair (don’t you just hate jaggies in characters’ hair?) The trouble, though, is that downsampling is substantially more expensive to implement than MSAA–after all, it literally involves running your game at a significantly higher resolution. As a result, while antialiasing coverage might be greater with downsampling, the actual anti-aliasing effect will be less pronounced since PS4 Pro titles will most likely downsample from 2x the resolution–a little higher than 1440p–compared to 4x MSAA, combined with post-process antialiasing.

Deferred renderers tend not to play nice with MSAA, but that’s another thing entirely. In any case, PS4 owners at 1080p might end up with the framerate and visuals, but just marginally better image quality. Nvidia DSR (Dynamic Super Resolution) and AMD VSR (Virtual Super Resolution) can give us a good idea of the potential image quality gains when downsampling on the PS4 Pro. While a 4x downsample (from 3840×2160 down to 1080p) undoubtedly offers fantastic AA coverage, a 2x downsample–more in line with what the PS4 Pro can offer–really can really feel like a waste of GPU power at times–much of your aliasing is still there and the only really noticeable side-effect is a reduced framerate.


The big question, though, is where will all this position the PS4 Pro in terms of the Xbox One S and the Xbox Scorpio? The PS4 Pro has a substantial headstart over the Scorpio–it’ll be in the market for several months before the Scorpio launches, giving Sony a tremendous early mover advantage. Pricing is also on its side, considering that the Pro debuts at the same competitive $399 pricepoint that we saw the original PS4 launch at. Considering the kind of hardware the Scorpio is set to pack, we find it hard to see Microsoft pricing its console any lower than this, with $450 or $499 being more likely pricepoints. The Pro is also dangerously close to the Xbox One S’s $350 retail price making that particular console even more irrelevant. The PS4 continues to sell like hotcakes, and if the market accepts the Pro as just another PS4 SKU, and not a separate console, we expect much of that momentum to rub off on the Pro–this should make itself evident in pre-order figures for the Pro.

We’ll update you here about that once we hear more. But again, the PS4 Pro’s 4K focus might just be its downfall–most people still game at 1080p, and, considering Sony’s commitment to ensuring that the PS4 and the Pro both retain gameplay parity, a lot of people might not see the need to shell out an extra $100 for what would be a largely identical experience. This policy might change later in the PS4’s life cycle, but as of now, the PS4 Pro simply doesn’t offer that much value for 1080p gamers, especially considering that a software update will enable standard PS4’s to support HDR as well. What remains to be seen is the kind of impact the Pro can make before the Xbox Scorpio hits the market.

What’s your take on the PS4 Pro? Let us know!

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