On Monday, Microsoft formally debuted the DirectStorage API on the Windows PC platform. The API supports direct data exchanges between the GPU, graphics RAM, and a storage media, allowing games to feed game assets to the graphics hardware in a more direct manner.
The API is compatible with both Windows 10 and Windows 11, with the latter being recommended by Microsoft for "in-built storage improvements." Unfortunately, current storage APIs were not optimized for this high number of IO requests, preventing them from scaling up to these higher NVMe bandwidths creating bottlenecks that limit what games can do. Even with super-fast PC hardware and an NVMe drive, games using the existing APIs will be unable to fully saturate the IO pipeline leaving precious bandwidth on the table.
That’s where DirectStorage for PC comes in. This API is the response to evolving storage and IO landscape in PC gaming. DirectStorage will be supported on certain systems with NVMe drives and work to bring your gaming experience to the next level.
Unfortunately, Microsoft has yet to release the game-changing feature of the DirectStorage API, GPU-accelerated asset decompression. This feature enabled GPUs to employ compute shaders to decompress game assets saved on disk in compressed asset libraries. To reduce their disk footprint, most games save their local assets in this manner. Without this functionality, unless there is specific game code from the developer's end to use GPGPU for asset decompression, compressed game assets must still rely on the CPU, lengthening the pipeline. Microsoft mentions it's on the to-do list.
If you want to get your PC ready to take advantage of DirectStorage games, we have a few suggestions. DirectStorage is compatible with Windows 10 devices, but Windows 11 has the latest storage optimizations built in and is our recommended path for gaming. While you may see benefits on any kind of storage device, installing games to an NVMe SSD will maximize your IO performance and help you more fully experience the benefits of DirectStorage. Stay tuned to learn about games that will be shipping with DirectStorage in the future!
This release of DirectStorage provides developers everything they need to move to a new model of IO for their games, and we’re working on even more ways to offload work from the CPU. GPU decompression is next on our roadmap, a feature that will give developers more control over resources and how hardware is leveraged. Additionally, we will continue optimizing, integrating feedback, and improving on the existing runtime implementation.