Gen4 SSDs featuring the recommended specs listed by Sony are almost indistinguishable from the PlayStation 5 internal SSD, according to Insomniac Games' Director of Core Technology Mike Fitzgerald.

　　Speaking on Twitter, Fitzgerald confirmed that Insomniac has already run some tests in Ratchet & Clank: Rift Apart with different SSDs that met the recommended specs, and the results were pretty impressive, as there was almost no difference in performance compared to the PlayStation 5 internal SSD.

　　The Gen4 drives we tried that met the recommended specs gave results almost indistinguishable from the internal SSD. The rest of the I/O path still in use (hardware Kraken decompression, etc.) is definitely pulling its weight in delivering the crazy loading moments in Rift Apart.

　　Insomniac also tested some Gen4 drives that did not meet the specs and confirmed slower load in some of the most SSD-stressing areas. As such, the developer suggests players keep a close eye on a drive's specs before purchasing it to expand the PlayStation 5 storage.

　　We tried some below-spec Gen4 M.2 drives as well and saw up to 15% slower loading in the most SSD-stressing areas of the game. Not too shabby, but keep a close eye on technical specs if you’re making an SSD purchase, as our game does rely on high-quality storage.

　　Last week, Sony released a new PlayStation 5 beta firmware that finally introduced M.2 storage expansion support, alongside some other new features. Sony also released the recommended specs for optimal performance.

　　Interface: PCIe Gen4 x4 M.2 NVMe SSD

　　Capacity: 250GB – 4TB

　　Cooling structure: Using an M.2 SSD with your PlayStation 5 console requires effective heat dissipation with a cooling structure, such as a heatsink. You can attach one to your M.2 SSD yourself, either in a single-sided format, or double-sided format. There are also M.2 SSDs that have cooling structures (such as heatsinks) built in.

　　Sequential read speed: 5,500MB/s or faster is recommended

　　Module width: 22mm width (25mm width is not supported)

　　Form Factor: M.2 type 2230, 2242, 2260, 2280 and 22110.

　　These numbers can be found on retail listings for M.2 SSD devices. The first two digits refer to the width, the remaining digits to the length.

　　The public release of the latest PlayStation 5 firmware update introducing M.2 storage expansion support has yet to be dated.