Sony details PlayStation 5 hardware and features

Sony announced several key details of its upcoming PlayStation 5 console. In a virtual keynote for Game Developers Conference 2020, game developer and Sony's lead system architect Mark Cerny spoke at length about all the new features coming to the console that is slated for launch during the Holiday season this year.

Before we continue, no, there were no images of the new console, so we still have no idea what it's going to look like yet. As this keynote was meant primarily for developers, it only talks about the technical features of the new console. The design and other aspects of the console, such as pricing, will be revealed closer to the launch period.

With that out of the way, let's begin to tackle the wealth of information revealed at the keynote today. One of the major new features of the PS5 is the next generation solid state storage, and it's also the aspect Cerny spent most time talking about.

Like the Xbox Series X, the PS5 will move away from the hard drive based storage of previous generation consoles to fast SSD storage. How fast are we talking about here? Sony claims raw I/O throughput of 5.5GB/s, which makes it roughly 100x faster than the storage on the PS4.

Having storage that fast has a number of advantages. It improves all load times tremendously, which means games launch faster, load faster and also speeds up things like reloading levels or fast travel. In turn this means developers don't need to have things like loading screens or the deceptive long corridors or elevator rides, which are currently necessary to hide the loading time for the next level. A storage this fast could load assets instantly, have seamless transitions, and basically change how games are made.

The faster storage also makes efficient use of the system memory. With the PS4, because the base hard drive was slower, most of the game assets had to be stored on the 8GB GDDR5 memory and would just sit there taking up space. With the PS5, the assets can be streamed in much faster, so only a fraction of the new 16GB GDDR6 memory has to be allocated to the assets.

One of the issues with hard drive based storage was also duplication of assets. Several assets had to be duplicated across memory blocks to reduce access times for that particular level. With flash storage, especially one this fast, that is no longer necessary, so theoretically games can now have smaller install sizes as less files will have to be duplicated.

A fast storage will also reduce the time spent installing a patch once it's download as patches can now be applied instantly.

Sony has also worked to reduce other aspects of storage performance on the PS5. Even if you installed an SSD on a PS4 right now that is 10x faster than your current hard drive, the performance boost would be 2x at best as the rest of the I/O chain is not optimized to take advantage of it. With the PS5, the entire memory operation from decompression to coherency, mapping, file I/O, and check-in and load management have been updated to work with the faster storage so you get the full benefit of the 100x improvement in memory speed.

As for how much total storage you have, Sony found that 825GB was the best figure to go with the 12 channel interface for the custom flash controller and also to keep the cost low. The custom flash controller goes to the custom I/O unit, which features a Kraken decompression unit (Kraken is a more modern and efficient compression standard used by PS5 alongside the ZLIB borrowed from the PS4), a dedicated DMA controller, two I/O co-processors, on-chip RAM, and coherency engine.

Now for the question of expandable storage. Unlike Microsoft, Sony will be supporting standard external USB drives as well as M.2 SSDs. However, there is a catch - the USB hard drives can only be used to play PS4 games on the PS5 and not the new titles made specifically for PS5. This is obviously because PS5 titles will be made with the new faster internal SSD in mind and cannot be run off the external hard drive.

As for the M.2 drives, Sony is currently in the process of evaluating which M.2 drives will work best for the console. M.2 drives based on the PCIe 3.0 standard will not work as they simply do not have the bandwidth to run native PS5 games. You will be required to use the new PCIe 4.0 M.2 drives that are coming out, which are currently relatively rare and very expensive but should go down in price over time as adoption increases.

Sony is testing these and will eventually be releasing a guideline for which of these drives are recommended for use with the PS5. The difference in the memory controller and architecture of these external drives and the use of two priority level vs. six priority level on the internal SSD means it's not easy to just pick any M.2 drive and slot into the console. Many of these drives also don't have a standardized design and may not even fit inside the internal SSD bay on the PS5. Due to this, the company recommended waiting for its SSD guideline to come out next year before purchasing any drive.

With the lengthy discussion regarding the storage out of the way, Cerny then moved on to some of the other hardware specifications of the console, namely the CPU and GPU and how they are configured to work this time around.

As we already know, the PS5 is based on an AMD SoC consisting of 8x Zen 2 CPU cores and a custom RDNA 2 based GPU. As with previous generation, the new PS5 has similar hardware to the competing Xbox Series X but how it is configured is very different and is what will eventually set the two consoles apart.

With the Xbox Series X, Microsoft chose to have high clock speeds and locking them down. Sony has a different approach on this, where the company is instead locking down the power target and letting the frequency fluctuate based on the workload. The console still has a limit, with the CPU clock speed capped at 3.5GHz and GPU at 2.23GHz, but these are the absolute maximum values and they will go down if the workload doesn't call for it.

Having power as your target makes things easier. The clock speeds don't go down if the console is running in a hot environment as the temperature isn't dictating the performance. And because the power target is locked, Sony already knows what the cooling requirements are going to be, so the cooling system is much better optimized for the hardware.

The GPU on the PS5 has 36 compute units and 10.28 TFLOPs of performance. It's worth mentioning that neither number is directly comparable to the figures from the PS4 due to the differences in architecture of the two GPUs and that newer GPUs can have lower floating point performance and still outperform older GPUs. However, it is also worth pointing out that Sony's figures are lower than those Microsoft announced couple of days ago, and in that case, the GPU is identical. This means, at least on paper, that the PS5 is weaker than the Xbox Series X, but we'll get to that a bit later.

Sony also talked about backwards compatibility. All PS4 games will be compatible with the PS5 without much work on the developers' side, and can be made to work even better with developer involvement. Developers making games exclusively for the PS5 also have the choice to take advantage of the new features found on the console, such as the geometry engine with its primitive shader support, or hardware accelerated ray tracing, or they can ignore them and make them just the way they did for the PS4.

Speaking of, the PS5 does have full support for ray tracing as it is part of the RDNA 2 architecture and unlike NVIDIA's graphics cards it doesn't use any dedicated hardware for it but just the compute units. With that, it can ray trace audio, global illumination, shadows, reflections or complete path tracing as seen in Minecraft RTX or Quake II RTX. Cerny said they managed to get reflections working in a PS5 game with minimal performance loss and we have already seen how the Xbox Series X handles it so it seems ray tracing is going to be a major feature on next generation consoles.

Cerny also briefly talked about power consumption and how the console has been designed to avoid the annoying fan whine on current PS4 consoles in certain games like God of War. Again, this is a function of the variable frequency boost feature.

The last thing Cerny talked about is audio, more specifically, 3D audio. The PS5 will feature hardware accelerated 3D audio with the use of a special co-processor called the Tempest 3D Audio Engine. This new feature is designed to provide extremely realistic audio with precise imaging and positioning for sound sources around you in a 3D space. Instead of relying on existing technologies like Dolby Atmos, which Sony claims only really work with dedicated hardware and are limiting, Tempest will provide a 3D audio experience with potentially any sound system, with current priority been given to headphones. Optimization for televisions and surround sound systems will be coming in later.

Tempest uses HRTF or Head Related Transfer Function to place audio based on the position and shape of your ears on your head. Since this cannot be realistically customized for every individual, the system will initially offer five presets and you can choose which one sounds best for you. However, Cerny mentioned that Sony is exploring the idea of having customers send in pictures or videos of their heads so they can create custom HRTF profiles for individuals that provide perfect positional audio customized for that person. Still, even without that, Sony claims Tempest 3D AudioTech will be a major innovation in game sound.

That was basically everything Sony covered in its keynote. As mentioned before, we still don't know what the console looks like and certainly not what it will cost. However, we do know most of the specifications now and that invites a lot of comparisons with the Xbox Series X that also exposed its internals quite literally just a couple days ago.

There is no denying that on paper the Xbox Series X is more powerful. While we still don't know just how many consoles Microsoft will have in its Series X, the flagship model they have been showcasing so far is certainly more powerful than the singular PS5 model Sony talked about today. This leads us to believe that we might be looking at a significant price delta between the two models, with Microsoft pricing the Xbox Series X much higher as has been expected while the PS5 coming in at a lower price. We don't want to speculate on what the exact numbers will be but we'd be shocked if these two consoles end up costing the same.

Still, the difference in actual gameplay might not be significant. While Microsoft's box may be able to push a few extra frames, the PS5, by all means, is also a powerful machine with basically the same hardware. It also impresses by having faster internal storage and seemingly cheaper external storage solution. However, the PS5 definitely doesn't have strong backwards compatibility as it's limited to PS4 while Microsoft will have Xbox One, Xbox 360 and even some original Xbox titles for the Xbox Series X.

But that's all for now. Hopefully, regardless of current global health concerns, both consoles will be able to make their launch deadlines this holiday season so we can have more to talk about then.

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