How PS5 and Xbox Series X Storage Works

The new generation will bring with it huge increases in CPU and GPU capacity, but this is common and normal with each new generation and doesn’t surprise anyone. What makes this generation more special than ever is the radical change in storage: consoles follow in the footsteps of the PC market by changing from mechanical disks to SSDs , but in this case they have gone a step further to obtain the greatest possible benefits of this fact, incorporating custom devices .

“Generic” storage for games

Solid state drives marked a revolution in the PC market, providing tremendous improvements in overall system responsiveness. Games benefited enormously from this in the form of faster installations and reduced load times, as well as a better response when games need to load data “on the fly”.

In recent times, NVMe SSDs have provided much faster on-paper speeds than SATA SSDs, but for gamers these benefits have not been much noticed. Conventional wisdom holds that there are two main causes for this: First, almost all games and their engines are designed to be playable from hard drives because current consoles and many low-end PCs lack SSDs. Game developers cannot take full advantage of the performance of NVMe SSDs without making games extremely slow for those still using mechanical hard drives.

Second, SATA SSDs are already fast enough to change the bottleneck in other parts of the system, often in the form of data decompression. Something other than SSD has to be accelerated before games can properly benefit from the performance of PCIe NVMe SSDs.

Storage on PS5 and Xbox Series X, a “top secret”

Both Microsoft and SONY have addressed these two issues in their new generation of consoles. Game developers are now free to assume that users will have very fast storage on both consoles and PCs, and in addition the new generation of consoles adds additional hardware features to address the bottlenecks that would be present if running on PCs mid-range with the latest generation SSD .

However, we are still grappling with both companies’ marketing strategies: Let’s be frank, both companies are overstating the capabilities of their consoles to try to attract users, and the actual data remains to be seen. Given that the consoles are completely closed platforms and that they are not even on the market yet, some of the more interesting technical details still remain a secret.

The main source of technical information about the PS5 (and especially about its storage) is Mark Cerny , its main designer. In March, he gave a one-hour technical presentation on the PS5 and spent more than a third of it talking about its storage. Less officially, SONY has filed several patents that apparently belong to the console, including one that lines up pretty well with what’s been confirmed about the PS5’s storage technology. That patent reveals numerous ideas that SONY explored in the development of the console, and many of them are likely to be implemented in the actual design.

Microsoft has taken the approach of glossing technical details in eyedrops through sporadic blog posts, and a few things with interviews. They’ve introduced brand names for many of their storage-related technologies (like Xbox Velocity Architecture for example), but in far too many cases we really don’t know anything about their specific features.

In addition to the official sources, of course there are the leaks, comments and rumors about the storage of PS5 and Xbox Series X that have helped feed much the hype of both consoles, but regarding the SSDs of the consoles in particular we know little or nothing, at least in terms of real and official data. That leaves us with many gaps that require an analysis of what is possible and likely to be included in upcoming consoles.

What we know about console SSDs

Microsoft and SONY use custom NVMe SSDs as storage on the PS5 and Xbox Series X, albeit with different definitions of “custom.” SONY’s solution aims to more than double the performance of Microsoft’s solution and is definitely more expensive despite having less capacity. Generally speaking, SONY SSDs will offer similar performance to high-end PCIe 4.0 PC SSDs, while Microsoft SSDs are more compared to more entry-level NVMe SSDs . Both are a huge step forward, however, compared to Xbox One and PS4 storage.

The most important and impressive performance metric for the SSDs on these consoles is their sequential read speed (write speed is almost irrelevant to gaming performance) and even when doing random reads it will generally be for large amounts of data and not for the 4KB blocks on which performance ratings are normally based.

Microsoft’s 2.4 GB / s read speed is 10-20 times faster than a mechanical disk offers, but it is well below current standards when it comes to high-end storage (an NVMe PCIe 3.0 x4 SSD offers 3.5 GB / s). For its part, SONY’s 5.5 GB / s is slightly higher than a PCIe 4.0 x4 NVMe SSD with Phison E16 controller, but everyone competing in the high-end SSD market has more advanced solutions on the way. This means that by the time the PS5 is on the market there will already be comparable performance solutions available for PC.

SONY has said that its SSD uses a custom controller with a 12-channel interface for NAND Flash memory. This appears to be the most important way in which its design differs from typical PC SSDs, as even high-end ones have 8 NAND channels (4-channel mid-range drives). Higher channel counts are more common in server SSDs, especially those that are designed to withstand extreme workloads.

That SONY has an SSD with more channels than usual means that its controller will be extraordinarily large and expensive, but on the other hand it does not need as much performance per channel to reach the 5.5 GB / s that they promise, and that means that they could use 64-layer TLC NAND chips , much cheaper and offering the same performance.

This 12-channel controller also leads to quite unusual capacities (825 GB). A console SSD does not require over-provisioning compared to PC SSDs, so 50% more channels should translate to 50% more usable capacity. The PS5 will have an 825 GB capacity SSD, which means that each channel of the controller will handle 64 GB of raw NAND, organized in a 512 Gbit (64 GB) die or two 256 Gbit (32 GB) per channel .

This means that the nominal gross capacity of the NAND is 768 GiB or approximately 824.6 GB. The usable capacity after taking into account the reserved area required by the console will be more in line with what a drive manufacturer would call 750GB of capacity , so SONY is overstating the capacity of its SSD.

It’s probably worth mentioning here that it’s not realistic for SONY to have designed their own high-performance NVMe SSD controller, just like they can’t do a CPU or GPU design on their own. SONY had to partner with a provider existing SSD controllers and undertakes custom, as he did with AMD driver, probably assembled from proven designs. Unfortunately, no one knows who that partner is.

The Microsoft SSD, meanwhile, will not boost performance beyond the new normal levels today on a PC, but in any case having 1 TB of capacity in an NVMe SSD of this speed in a console is a triumph For the users. Multiple sources indicate that Microsoft uses a standard SSD controller from one of the usual agents (possibly a Phison E19T), and the unit itself would be made by one of the leading players in this market. However, the storage for the Xbox Series X (and PS5) is quite likely to have a form factor and custom firmware .

Neither of the two manufacturers has provided official information on the storage of their respective consoles other than what we have already mentioned. SONY is quite committed to using TLC chips, and Microsoft’s lowest performance target makes us think that its best option would be NAND QLC. The best option for Microsoft’s expected performance would be to use a 4-channel controller with TLC chips, actually. Ultimately, in the future either of the two consoles could have a double capacity version if they use QLC NAND memory to maintain the same performance.

What about the ability to expand storage on PS5 and Xbox Series X?

Both Microsoft and SONY will offer the possibility of expanding the storage of their respective consoles. Microsoft’s solution is to repackage your SSD in a removable form factor that is reminiscent of when consoles used memory cards to save games. Given that it uses the same components, these expansion cards would be functionally identical to the internal storage of the console, but the disadvantage is that Microsoft will control the supply and probably with it its price. Seagate is currently the only confirmed partner to sell these proprietary expansion cards.

For its part, SONY looks like it’s going to take the opposite approach by giving users direct access to a standard M.2 PCIe 4.0 slot that will support storage expansions from all kinds of manufacturers. However, the requirements are not entirely clear, since SONY has said that it will perform compatibility tests with third-party units and publish a compatibility list, but they have not said if the PS5 will directly reject units that are not in that product list. approved.

To enter the SONY Compatibility List for the PS5, the unit will need to be mechanically tuned (i.e. not having a large heatsink, square dimensions, etc.) and offer at least as much performance as the internal SSD offers. the console. The performance requirements imply that no unit currently on the market could meet these requirements, but as we mentioned before, by the time the console is released, there will surely be units available that do.