Windows 10 will support DirectStorage, but with limited functionality
Even though the NVMe standard is showing some impressive bandwidth advancements with great IO speeds, the technology is not really used to its full potential as of yet. Sure, we can see things loading faster in games and sequential read/write speeds are substantially improved over SATA SSDs when transferring files, yet the software support is lagging behind. Microsoft proved that the NVMe can make a huge difference with the implementation on the new Xbox Series X consoles that benefit from the DirectStorage technology. Game loading times thus see an x40 improvement over old HDDs on the new Xbox consoles, whereas PCs still only see 1.5 - 3x improvements. With the introduction of Windows 11, Microsoft is bringing the DirectStorage API to PCs as well. Now, it looked like this would be a Windows 11 exclusive feature to force users to jump on the new OS, but Microsoft recently clarified that DirectStorage is also coming to Windows 10. However, there is still an incentive to migrate to Windows 11, as the Win 10 DirectStorage implementation will not be as fast.
The Windows 10 compatibility is ensured through the DirectX 12 Agility SDK working in tandem with the DirectStorage SDK. Windows 10 version 1909 and up will receive DirectStorage support, but the overall speed will be somewhat affected by the legacy OS storage stack. The full DirectStorage potential will only be unlocked on Windows 11 via an upgraded OS storage stack.
Borrowing from the DX 12 batched submission/completion calling pattern, the new DirectStorage API can relieve applications from the need to individually manage thousands of IO requests/completion notifications per second through the CPU. This technology can also speed up GPU decompression and improve graphics asset load times (mostly texture-related) and streaming scenarios, but such features will be added closer to the official Windows 11 release.
In the meantime, game developers are encouraged to add DirectStorage support to existing PC-specific game engines through the DirectX 12 Ultimate SDK in order to facilitate the transition to near-instantaneous game load times and greatly reduce the texture pop-in effect for GPUs.