Sony and Microsoft may use PCIe 3.0 SSDs in tandem with Optane-like cache technology to accelerate data in their next-gen consoles, leading to massively improved load times, revolutionary asset management for developers, and lowering the console's overall price point for consumers. Or they could use tiered storage to combine an HDD and SSD as a cost-effective solution that doesn't sacrifice speeds.
We originally thought Sony and Microsoft would use new PCIe 4.0 SSDs in their next-gen PlayStation 5 and Project Scarlett consoles. We've heard both companies rave about their ultra-fast storage, and PCIe 4.0 can hit up to 32GB/sec transfer rates on 8x lanes. But this seems like overkill. Although the Zen2+ chips in next-gen consoles natively support PCIe 4.0, Sony and Microsoft may not really need to leverage it.
They could stick with PCIe 3.0 over NVMe or even SATA drives and still have a noticeable jump from current mechanical HDDs. PCIe 4.0 SSDs are pretty expensive, and if included in new consoles, the PS5 and Scarlett may not hit their rumored $499 price tags.
So if the PS5 and Project Scarlett don't use PCIe 4.0 to hit insane speeds, what will they use? There are some possibilities. We could see a single M.2 NVMe PCIe 3.0 SSD, or a hybridized SSD and HDD with tight cohesion and synergy with other components via tiered storage.
We could even see a custom onboard cache module similar to Intel's Optane tech, and it just so happens Sony is developing its own ReRAM SCMs.
Before we can talk about what PlayStation 5 and Project Scarlett's storage will be like, we have to understand how caching and tiered storage works, and how it's advantageous for current system builds.
Fair warning, this is a big article, and there's a chance we're completely wrong about this.