Sony has pretty clear requirements when it comes to the read speed of SSDs that can be used to expand the storage of its next-gen PlayStation 5 console. In a new video, Digital Foundry has now tested what exactly happens to the console's gaming performance when you install a PCIe 4.0 SSD that does not meet Sony's required specs.
https://www.notebookcheck.net/Video-shows-what-happens-when-you-buy-a-too-slow-SSD-for-your-PS5-storage-expansion.563774.0.html