Microsoft has announced the public preview of DirectStorage 1.4 alongside the first public preview of the Game Asset Conditioning Library, a combination designed to introduce Zstandard, or Zstd, as a new compression format for game assets on Windows. On paper, this innovation aims at three specific goals: improving data compression, reducing load times, and enabling smoother resource streaming in titles with large worlds, heavy textures, and constant data demands from storage.
This news matters because DirectStorage is not a minor tool in the PC gaming ecosystem. Since its arrival on Windows, this technology has been positioned as a way for games to better leverage the speed of NVMe SSDs, moving multiple gigabytes per second with less CPU load. In other words, it aims to shift the bottleneck from disk access management to a more efficient data chain between storage, memory, and GPU.
More Than Just a New Codec for File Compression
The main innovation in DirectStorage 1.4 is its support for Zstd within its multi-level decompression framework, enabling decompression on both CPU and GPU. Microsoft states that Zstd was chosen for its combination of factors: good compression ratios, competitive decompression performance, broad software and hardware support, and widespread adoption outside of gaming. Notably, Zstandard is an open algorithm, with a stable format published as RFC 8878, which may facilitate its adoption in tools and pipelines beyond proprietary solutions tightly linked to a single provider.
Alongside Zstd support, Microsoft has also released the base code for its GPU decompression shader for Zstd in the DirectStorage repository. Currently presented as an initial reference, it is still in development and optimized mainly for content blocks of 256 KB or less, aligning with modern asset packaging patterns aimed at streaming. The goal is to serve as a starting point for manufacturers and developers to refine future implementations across different graphics architectures.
The second part of the announcement is the new Game Asset Conditioning Library (GACL). Here, it’s important to keep expectations realistic: Microsoft claims that this library can achieve up to a 50% improvement in Zstd compression ratios for certain assets, but this figure should be viewed as a maximum under specific scenarios, not a guaranteed gain in every game. The library integrates into the content pipeline and applies pre-compression conditioning techniques—both lossless and with controlled loss—including shuffling, BLER, and CLER, the latter supported by machine learning to improve results.
In this initial phase, DirectStorage 1.4 can transparently reverse these transformations for BC1, BC3, BC4, and BC5 textures. Support for BC7 remains for later: the GACL repository mentions experimental compatibility in the library, but undoing this transformation at runtime is not yet available in DirectStorage 1.4. This distinction is important because it makes clear that the announcement outlines a roadmap, but does not yet provide a comprehensive solution for all common PC texture formats.
Why It Could Change How Games Are Loaded
The real interest of this update lies not just in higher compression, but in better compression without increasing decompression costs during gameplay. For modern titles—especially open-world or highly detailed scenarios—the experience increasingly depends on delivering small data fragments quickly: textures, geometry, LODs, shaders, or audio. If these assets occupy less disk space and can be decompressed efficiently, games can load faster, move more content in the background, and rely less on CPU resources.
There is also a historical perspective. DirectStorage arrived on PC in 2022 as an initiative to modernize data I/O on Windows; that same year, Microsoft added GPU decompression with DirectStorage 1.1 and GDeflate. Later, in July 2025, DirectStorage 1.3 introduced EnqueueRequests, giving developers greater control over how data requests are launched and synchronized. Version 1.4 continues this evolution by supporting D3D12 CreatorID globally, improving command queue grouping and more predictable GPU workload scheduling.
However, it’s important to set realistic expectations to avoid false hopes among gamers. This does not mean that any game using DirectStorage will magically improve just by updating drivers or replacing DLLs. Microsoft has clarified that DirectStorage 1.4 features require game assets to be generated and compressed with Zstd, optionally conditioned with GACL during the build process, and for developers to explicitly integrate the API into their titles. For end users, improvements depend on developers adopting and integrating this technology.
Additionally, the baseline requirements should not be overlooked. Microsoft notes that DirectStorage requires the game to use the API, run from an NVMe SSD with the standard NVM Express driver, and feature a compatible GPU supporting DirectX 12 and Shader Model 6.0. While these specifications align well with modern PCs, this alone does not make any system fully prepared for the new data flow.
A Promising Preview but Still a Work in Progress
The announcement also comes with the usual cautions of a preview. The official NuGet package documentation mentions known issues: staging buffers larger than 256 MB may cause unexpected failures on some GPUs, and the fallback shader for GPU decompression of Zstd is still in development and may trigger TDRs on certain compressed content. These are understandable limitations early in development but serve as reminders that this technology is still in testing, not a final product.
In the medium term, Microsoft’s key strategy hinges on support from GPU manufacturers. AMD, Intel, NVIDIA, and Qualcomm have confirmed they are preparing driver-specific optimizations for Zstd during 2026, which should improve decompression performance on actual hardware. If this work materializes and developers start integrating it into their pipelines, DirectStorage 1.4 could become one of those under-the-hood improvements—less flashy than a new graphics engine but highly impactful for end-user experience: less wait, more data in motion, denser worlds without additional CPU load. For now, technological momentum points in this direction, but the definitive test will come with the first games that truly utilize it.
Frequently Asked Questions
What is DirectStorage 1.4, and how does it differ from previous versions?
DirectStorage 1.4 is Microsoft’s latest public preview of technology designed to accelerate data access in Windows games. Its key features include support for Zstandard as a compression format for assets, integration with the new Game Asset Conditioning Library, and developer control improvements such as global support for D3D12 CreatorID.
Will gamers see improvements just by updating drivers or Windows?
Not necessarily. Microsoft explains that the new features in DirectStorage 1.4 require that game assets be explicitly prepared with Zstd compression and possibly conditioned with GACL during build, as well as explicit API integration by the developer. Additionally, the game must run from an NVMe SSD and have a compatible GPU supporting DirectX 12 and Shader Model 6.0 for full benefits.
What is Zstandard, and why is it relevant in gaming?
Zstandard is an open compression algorithm known for providing good compression ratios and fast decompression speeds. In gaming, it helps reduce asset sizes and accelerate loading and streaming times, especially when combined with DirectStorage and GPU processing.
Does the Game Asset Conditioning Library work with all textures now?
No. In this first preview, DirectStorage 1.4 supports reversing GACL transformations on BC1, BC3, BC4, and BC5 textures. Support for BC7 is not yet fully implemented at runtime, though the library already includes experimental support in that direction.
via: devblogs.microsoft, nuget.org and zstd