If there is a technology that defines the new generation of consoles, it is undoubtedly the SSD with its enormous speed, but the counterpart is having little storage, which forces to have a limited collection of games in the console’s memory. On a console that inherits the huge collection of its predecessor and promises to have a huge catalog, this is a problem.
PS5 games require the SSD to work
All games for PlayStation 4 are designed so that data streaming from the disk is done according to the bandwidth of the hard disk of said console, which is where the games are installed. This means that the amount of information that is transferred from the SSD storage to the RAM must be made explicit in the game code.
The PS5 SSD has a communication speed of 5.5 GB / s, the PS4 HDD instead makes use of an internal USB interface to transmit the data. And yes, surprisingly enough, it is not SATA. The transfer speed? Theoretical 5 Gbits / s, but due to the limitations of the hard drives, the average is 150 MB / s.
So we are facing a difference of an order of magnitude in the transfer of data between storage and RAM. To all this add the support of on-the-fly data compression and decompression systems and we can find transmitted information rates from 9 GB / s to 20 GB / s thanks to compression systems such as Oddle Kraken. It should be clarified that data transmission rates are not the amount of data but the speed at which they move.
Another factor is the search times on a conventional hard disk, which add latency in the search and the transfer of data between these and the RAM. All of this is not exclusive to PS5 and its SSD, but it also happens on Xbox Series consoles, where games cannot be played from the SSD either.
Latest update doesn’t fix PS5 storage issues
SONY has just updated the console with a feature, the ability to move data from the SSD to an external hard drive via USB. The controversy? For the reasons that we have discussed in the section above, PS5 games cannot be played from external USB, which should not be a surprise to anyone who knows the operation of any of the new generation consoles, but a cumbersome if we want to have several games installed.
The fact of being able to move the information from the SSD to a USB hard disk not only serves to make backup copies and not have to wait to install the games again, but it also works for PlayStation 4 games, which work perfectly from these discs by not needing the low seek times and bandwidths of PS5 games. In reality, the SSD does little in games intended to run on an HDD with a transfer speed of 150 MB / s, beyond speeding up load times.
On the other hand, we must bear in mind that SONY has not yet updated the console to be able to expand its SSD storage. So its users are limited to 667 GB of storage. This forces many to have to move their PS4 games to USB to get the necessary space to play.
What prevents SONY from allowing the internal capacity of the PS5 to be expanded?
Officially they have not given an answer, but it must be taken into account that SONY has to certify the different M.2 units that come out for the console. Let’s not forget that the expansion port is internal and is necessary in a unit of this type with bus. PCI Express 4.0, is well cooled, that input already limits the number of compatible units.
The other problem is the fact that contrary to what happens in the Xbox Series X and S, where the internal and external storage have access to the SoC of the console, in the case of the PS5 SSD this is not the case. The expansion SSD connects with the custom flash controller that the console has and not directly with the SoC, this means that the search for data in the M.2 NVMe SSD is not done by its flash controller, but by the console’s flash controller, which requires adapting the unit in advance.
This leads us to think that none of the PCI Express 4.0 SSDs are compatible unless they have a firmware update. In any case, SONY should have already sent a list of requirements to SSD manufacturers. Although we will have to wait until summer to see if the PS5 storage problems have been fixed.