In an interview with VG247, Epic Games admitted that it rewrote parts of the game engine’s I/O subsystems in order to take full advantage of the PS5’s SSD speeds. At the core of the PS5, the beating heart of the next-generation console is based both on AMD’s 7nm Zen 2 CPU and RDNA2 GPU technology. As well as the new PCIe 4.0 interface for lightning-fast transfer speeds. Technically speaking and on paper, the PS5’s SSD is able to move compressed data at a speed of 9GB/s; for context, that speed is twice as fast as the Microsoft Xbox Series X’s 4.8GB/s. For decompressed data, the PS5’s SSD is still quite the beast, moving said data at 5.5GB/s.

As you know, prior to the PS5 and Xbox Series X, current-generation consoles and its predecessors shipped out not with an SSD, but with the traditional but slower HDD as the storage medium of choice. And while consoles like the PS4 Pro does support the much speedier SSD, it remains an after-sale alternative that console owner have to manually switch on their machines. (Source: VG247, Techspot)

Epic Games Reportedly Forced To Rewrite Portions Of Unreal Engine 5 Because Of The PS5 SSD - 8