On March 18, 2020 in the absence of a Game Developer Conference event and with no E3 this year Sony took it upon themselves to host a new event they called The Road to PS5 which was primarily a dev-facing livestream providing technical specs and data on the details of why and how the PS5 works the way it does. I will warn you ahead of time, this is all very complicated subject matter most of which gamers don’t need to know, and even some of which devs won’t understand. But if you have a love and passion for tech we encourage you to take a closer look at what was shared.
The short version is PS5 will not be weak, it has a lot of custom hardware and software powering it, and it is not simply a half-baked PC thrown together with a PlayStation logo. However, Mark Cerny also reinforced what smart people have been telling us all along, which is that TFlops from last gen consoles are not comparable to that of new consoles, and CU counts are not either. To find out more, take this journey with us inside the brains of the PS5 console.
Mark Cerny spoke with a genuine, honest tone and was mostly good at making complex concepts palpable by telling viewers the benefits behind each spec, but there are a few extremely knowledgeable slides here which may leave some puzzled. It is important that as gamers we at least absorb some of this information as we have traditional measuring sticks becoming useless to tell what is needed for each individual pipeline making up the consoles, wearables, computers, and handheld devices we enjoy games on.
Jim Ryan, SIE President & CEO, took stage in a small gathering (although the audience may have been photoshopped in via green screen) and introduced Mark Cerny, Lead System Architect of PS5, who then began to speak about PlayStation and console hardware engineering in general. He admitted the PS3’s faults in being so powerful but equally hard to develop for which was what changed with PS4 taking on the x86___64 architecture.
After that, he introduced the three pillars of PS5’s console design; Listening to developers, balancing evolution w/ revolution, and finding new dreams. These pillars were expanded upon and a huge deep dive of hardware information was given which is mainly aimed at developers.
LISTENING TO DEVELOPERS
This first pillar was described as enabling the desire of developers to facilitate the hardware design. The feature most requested by devs was SSD. A lot of problem solving was required to make this happen.
BALANCING EVOLUTION W/ REVOLUTION
Dead time before assets and game development engines are properly up and running has been a measurement the team at PlayStation are using and trying to reduce that dead time to zero.
Due to this, overall architecture cannot change much, this is what makes hardware designers somewhat handcuffed, with PS4 being a good balance but the GPU being a pain point. Sony had to be careful to prevent it being confusing for PS5. They have made it so that developers comfortable with PS4 do not need to use any of PS5’s additional features and can still make games without any new learning needed. Some of PS5’s new GPU power will even be implemented automatically behind the scenes.
FINDING NEW DREAMS
- Vastly improved audio, “3D audio” – Sony has always been dreaming of this and setting steps along the path. This is the new frontier for the PS5 in terms of doing something that the previous PlayStation consoles could not do.
SSD VS HDD
The mechanical hard drive for all of its woes saved PS4 from its slow Blu Ray drive which could not stream game data fast enough to be useful for that purpose. However, the limits of the hard drive were hit immediately. Even with zlib decompression, hdd’s are known to spend 2/3 of their time seeking and only 1/3 of their time actually loading data. It took 20 seconds total for 1GB to be streamed through PS4’s hard drive.
On an SSD there is essentially “no seeking” as we know it today. It only takes 1 second for 5GB to stream through PS5 instead of 20 seconds for 1GB on PS4. That’s 0.27 seconds per 1gb for PS5. The elimination of boot up load times, level load times, pop-in, etc. is thanks to this but the primary reason for SSD is that it gives the game designer freedom. There is also less quarantine of art assets to load and unload the memory.
Ultimately, Sony set out to eliminate loads for players and to make the SSD so fast that textures and objects can load entirely in half a second rather than loading and unloading while making players walk down narrow paths or take elevators to mask the loading.
Sony clearly tried to see if they could use HDD instead to create a streaming system, but it just wasn’t possible without SSD. Keep in mind, game limits to run speed, drive speed, flying speed are all due to this!!! That is why SSD technology will change console gaming forever especially in open world titles where traversal has always been a problem and even “fast travel” caused load screens.
Additionally, patches and games patched too often are having problems which were due to the HDD and the SSD will fix this, no need to install the patch in the same ways as before.
The PlayStation 5 will ship with 16GB of Shared GDDR6 Memory. And it doesn’t need as much of an increase this generation thanks to these SSD improvements. RAM previously on PS4 had to keep everything needed for the player’s next 30 seconds of action otherwise it would hang and slow down when unexpected things happened. PS5 can load it so fast it can just use the rest of its memory for 3D work and processing needs rather than parking assets and textures near the player.
CUSTOM EMBEDDED HARDWARE
With the SSD, PS5 must process way more information and could bottleneck easily. Custom chips are included on PS5 to solve this.
- Custom Flash Controller – multiple priority levels for audio, textures, etc. so that the right things are loaded in the right order. Balancing between cost effective and what was needed.
The team examined games being played and whether that set of games can be installed, reinstalled, patched, and played without problems given the current PS5 setup.
MAIN CUSTOM CHIP + I/O CHIP
zLib PS4 compression versus zLib PS5 compression has also seen improvements with Kraken from RAD Game Tools, zLib’s smarter cousin, using similar types of algorithms but 10% better compression.
- Custom I/O Chip features completely dedicated to reducing input lag while all of the complex data is going on (9 zen cores equivalent).
- Dedicated DMA Controller
- Additional Embedded SRAM
- Coherency Engines
Fully PCIe 4.0 implemented coherency engine to inform the GPU of memory address and custom cache flushing “pinpoint evictions”. Mark Cerny also bragged that devs don’t need to know any of this, it will all work seamlessly in the background and is compatible with all existing tools like Unreal Engine 4 for 100 times faster I/O than PS4. No load screens, super fast streaming, no pop-in, thanks to custom hardware created through collaborations between Sony and AMD.
PlayStation 5 will have a custom 5GB/s 825GB SSD built-in and is expandable when PCIe 4.0 drives become available.
How to expand storage:
- Large external HDD can be used for older games thru backwards compatible
- *Certain M.2 SSDs will be supported on the PS5 as well for expansion with full support of custom chips since they plug directly into the co-processors.
*The M.2 SSDs must be a flawless speed though. M.2 drives with PCIe 4.0 which can achieve 5GB/s and must physically fit within the internal bay. NVMe priority scheme will not be used since it has 2 priority levels and PS5 has 6 priority levels. Right now Sony is benchmarking and compatibility testing M.2 drives and when games reach beta on ps5 sony will begin to let the public know which SSDs are appropriate for PS5.
However, this will probably be after launch and sony asks gamers to wait for buying one until the better drives release and they designate which drives work best. Thanks to the dedicated custom hardware PS5 uses, the SSDs they certify will be able to use all of the extra features and speed of PS5, making it well worth the wait!
PS4 BACKWARDS COMPAT. + PS5 GPU
AMD created the backwards compatible program for Sony PlayStation 5 and all new features on PS5 are optional allowing Ray Tracing or ignoring RT. Mark began to get a little shy at this point in the presentation and although we get a huge deep dive on the Tempest AudioTech Engine and its custom hardware chip in the PS5 (designed by Sony) you will notice that there are less details from here on out, making this presentation primarily centered around the SSD and Raytraced Audio segments.
Another topic well described though, was reduced power consumption on RDNA 2.0 custom hardware. Mark went on to explain that all RDNA 2.0 GPUs can be vastly different, AMD changed what they were doing based on Sony’s PS5 needs and ended up using some of these new concepts on PC but left other more specific features on the PS5.
PS4 and PS5 both have 8 CPU cores but are nowhere near the same in power, so Mark reminds us that there’s a 62% larger CU transistor count between generations and this is in addition to the reasoning behind why TFlops are no longer a useful form of measurement.
In regards to legacy support, PS3 originally launched with an entire PS2 inside of every unit, this was ridiculously expensive and had to be discontinued. PS5 will be able to include all PS4 software libraries, but noticeably, Mark Cerny did not go into any detail about rumors of backwards compatibility for PS1, 2, and 3 games on the PS5 – we will have to wait and see since this is not a consumer-focused conference and instead was largely content meant for GDC attendees who must now work from home with hardware manufacturers to get the next-generation of games off the ground!
On a title by title basis testing is still needed but the top 100 PS4 titles as ranked by play time are almost all playable by launch on PS5 according to Mark Cerny. This should provide a much smoother experience for console upgrades and those with limited library or a large back catalog of games they would like to complete still using newer hardware rather than lugging out and plugging in an older console they could otherwise sell or store safely for future.
- Primitive Shaders + Geometry AI Engine – Devs don’t need to use all the new power of the PS5 GPU (Raytracing, etc.) if they aren’t ready for it just yet and instead have helpful AI tools which can do it for them so they can develop the game like a standard PC or PS4 game but still get the benefits of PS5.
HARDWARE SUPPORTED RAYTRACING
Mark Cerny announced “Intersection Engine” on PS5’s GPU CUs; memory intensive logic heavy code supporting the following:
- Audio Ray Tracing
- Global Illumination
- Full Ray Tracing
Different levels are going to be achieved for different games, but some PS5 titles using complex animated scenes with Full Ray Tracing are already running along behind the scenes and doing well. Mark tells us it will be a balancing act on a per game basis by devs.
IN THEORY (MARK CERNY MATH)
The preference of performance to high clock speeds (frequency) is compared with that of having higher bandwidth (threads). Hypothetical numbers were used to show this but we will not show those here to avoid confusion. Power and heat issues arise with the design of consoles, this was previously done with guesswork compared to the PS5’s precision in design knowledge. Instead of preset modes created by humans for the PS4 to switch between for fan speeds, internal temps, etc. the PS5 can do everything with a high intelligence according to Mark Cerny.
The PlayStation 5’s GPU uses 36 cu’s (which Cerny tells us equates to 58 PS4 cu’s) and use what sounds like an incredible variable frequency for what is needed at any second, constant power and a cooling system he promises to be cost effective and high performance. We may end up seeing the grill design after all based on how much emphasis was put on this, but then suddenly he let us know that it will be revealed soon as part of a “PS5 Teardown”.
RAYTRACED AUDIO + VR PRESENCE
- Custom PS5 Audio Processor – This is all accomplished by a special hardware chip called Tempest AudioTech similar to SPU programming conceptually seen in the PS3’s CELL chip. The custom PS5 audio chip is more powerful than the PS4’s entire circuitry combined!
PS5’s Custom Audio Processor also includes hundreds of advanced sound sources which can be modulated and used, Dolby Atmos only supports 32 at this time by comparison.
- Concept of locality
- Where the audio is coming from
- 3D effect on audio
- Part of the ray tracing stack
- The Tempest Engine itself
This processor can also be used for algorithms processing by devs if 3D Audio is not being used in the game. A custom AI can also be run on the processor by choice which helps adjust for different audio devices, headphones, tv, soundbar, sound system, full surround etc as part of the new Audio Ray Tracing effect.
FUTURISTIC AUDIO VISUAL DESIGN LAB
One other behind-the-scenes moment that Mark Cerny shared which was very abstract and hard to comprehend for someone who isn’t intimately familiar with how technology meets the human ear in the latest cutting edge examples. We believe that basically Sony has realized people don’t all hear the same, and now an AI is checking your hearing and changing the game engine to adhere to that. Exactly what will be needed for this to happen (is it only on the headphones at this time?) we don’t know yet.
Update: Out of the box PS5 supports a variety of HRTF, with the ability for more to be added later (including the potential of a tailor made HRTF for each player).
Mark Cerny then went on to add confusion to that topic by stating that they could even have a neural image of an ear or the brain to help produce games feeling more and more real at a later time.
This is the start of some great technology ladies and gentlemen, which can eventually lead us to that infamous PlayStation 9 commercial Sony put out which sees a future of full immersion Nerve VR style gaming. But for now, it’s just a very confusing explanation of how some of the next steps in technology include chasing this sense of presence with higher and higher realism over time – even on consoles.
In conclusion, we have received a lot of great new information about how the graphics chip for PS5 works. This was sandwiched with a lot of explanation about how and why to measure performance of the PS5 in certain ways, which made sense and fought a fair argument that PS5 is powerful as hell – ignore TFlops!
The amount of detail that was given to how this console works was impressive and proves PlayStation 5 is a true work of art. The raw engineering detail given by Mark Cerny was astounding and presented in ways which are exciting to hardware obsessed geeks like myself, and more importantly the studios which will make a lot of our next hit games over the next 4 – 7 years.
Custom hardware, custom software, firmware details, and even the layout of chiplets as well as an explanation on how AMD and Sony work together were all highly appreciated and completely eased any lingering doubts that the PlayStation 5 would be in any way lacking in modernization, innovation, and overall quality. Mark Cerny provided a statement regarding price that the design team has a responsibility to the gamer to keep costs under control, and Sony did not pull the trigger on being the first to price their console publicly. Rumors are still abound, but for now, we will wait for more. It’s safe to get excited about the PS5 again, it’s looking great.
OFFICIAL ROAD TO PS5 PRESENTATION
Update: Digital Foundry has now released an expert tech analysis:
Update #2: Digital Foundry has released further revelations: