The next-gen PlayStation 5 console won't be compatible with expandable M.2 SSDs at launch, Sony re-confirms.
A while back, PS5 architect Mark Cerny confirmed Sony's next-gen system wouldn't support M.2 expansion drives right at launch. The PS5 is compatible with third-party PC-grade PCIe 4.0 SSDs, but there's lots of compatibility testing involved, especially considering the PS5's SSD features a custom 12-channel memory controller. Cerny also confirms the expansion SSD has to be at least as fast as the PS5's 5.5GB/sec, which is absolutely feasible--there's SSDs that now hit up to 7GB/sec transfers.
"The NVMe scheme is pretty nice, but it only has two true priority levels. Our SSD has six. We can hook up a drive with only two priority levels but our custom I/O unit has to arbitrate the extra priorities rather than the M.2 drive's flash controller. And so the M.2 drive needs a little extra speed to take care of issues arising from the different approach," Cerny said in an early March presentation.
Cerny also told consumers to hold off on buying any NVMe SSDs for the time being. Sony will announce which drives are officially compatible sometime in 2021.
Read Also: Understanding the PS5's SSD: A deep dive into next-gen storage tech
Now Sony is re-confirming the info. The PlayStation 5's M.2 expansion bay won't actually work until Sony flicks the on switch with a firmware update. "This is reserved for a future update," Sony told The Verge.
This effectively means the PlayStation 5's ultra-fast SSD storage is limited to just 667GB for games, apps, and content. That's roughly 77% of the advertised 865GB storage space. The reduction is due to drive formatting, operating system files, and other features that reserve critical system storage space.
The Xbox Series X however uses a slower 2.4GB/sec TLC NVMe flash storage solution set in a CFExpress card design. Basically the Series X/S consoles use SSD memory cards that can easily be slotted in. But there's a downside: The cards cost $217 for 1TB of storage.