Mark Cerny, the lead architect behind the development of the PlayStation 5, has shared the internal SSD drive he has plumped for in regard to expanding the storage on his own PS5 console. Cerny had to select a drive that could match or outpace the PS5's own 5.5 GB/s-capable SSD, so it seems he selected a 7,000 MB/s-capable drive from Western Digital.
https://www.notebookcheck.net/PlayStation-5-lead-architect-Mark-Cerny-shares-his-7-000-MB-s-SSD-of-choice-for-his-personal-PS5-console.552970.0.html