Microsoft says the DirectStorage 1.1 API is coming soon to Windows PCs. With this release, Microsoft will enable GPU Decompression on PCs per its previously shared roadmap. The primary benefit of GPU Decompression is that PC gamers could see load times reduced by as much as 40% depending on the game and the PC hardware configuration.
DirectStorage 1.0 was introduced for Windows (10 and 11) in March 2022. It was designed to bring speed, bandwidth and latency optimizations to the Windows storage subsystem, which would scale with storage performance. Thus faster storage, like the latest NVMe SSDs, deliver greater overall benefits. Version 1.1 of the API builds on this promise with GPU Decompression, reducing the processing of graphical assets using the CPU and moving this workload to the GPU, which is adept at massively parallel processing and decompression tasks.
Microsoft explains in its DirectX Developer Blog that modern games typically require massive amounts of data to build and render the immersive worlds we navigate. This could mean hundreds of gigabytes of compressed data loaded to run the latest AAA titles. “When a game is run, the assets are transferred to system memory, where the CPU decompresses the data before it is finally copied into GPU memory to be used as needed,” says Senior Microsoft Program Manager, Cassie Hoef. “The transfer and decompression of these assets on gaming devices contributes heavily to load times and limits how much detail can be included in open world scenes.”
DirectStorage 1.1 has an optimized GPU-powered decompression algorithm to deliver loading performance benefits of up to 40% to the PC gaming experience. To back up its claims, Microsoft built an optimized demo where scene loading was up to 3x faster, and CPU loads were drastically reduced. Above, you can see a GPU with GDeflate (left) loading a scene in 0.8 seconds versus the CPU with Zlib (right) taking 2.36 seconds.
DirectStorage was initially described as a Windows 11-exclusive technology before Microsoft caved and facilitated its use in Windows 10 gaming experiences. Like the previous 1.0 version of the API, there are still said to be “additional optimizations in the IO stack available to Windows 11 users.” A DirectX 12-capable GPU supporting Shader Model 6.0 is necessary, and users should have game data on a high-speed NVMe SSD for optimal gains.
It will be interesting to see this technology applied in modern games, as in many titles on my mainstream 2022-built PC, it is the GPU that is usually maxed out, not the CPU.
Developers will be able to play with DirectStorage 1.1 later this year, and when it goes mainstream, we expect GPU driver updates from all major players. Please don’t hold your breath, though, as we are yet to see even one AAA game with DirectStorage 1.0 support released on Windows. Forspoken, by Square Enix, was going to spearhead DirectStorage on Windows this month but has been rescheduled for late January 2023.
