Microsoft used its DirectX State of the Union session at GDC 2026 to announce DirectStorage 1.4, the latest update to its storage API for Windows PCs. The release arrives alongside the Game Asset Conditioning Library, known as GACL, and together they introduce Zstandard compression as a new option for game assets, promising faster load times, smoother asset streaming, and significantly leaner game files. It is one of the most substantial updates the API has received since its debut.
DirectStorage was designed to accelerate game asset streaming on Windows PCs by reducing the CPU overhead involved in loading and decompressing game data. The technology routes assets more directly from storage to the GPU, cutting out the bottlenecks that older workflows introduced. The API first arrived on PC in 2022 as an initiative to modernize data input and output on Windows, and has been evolving steadily since.
DirectStorage 1.1 added GPU decompression with the GDeflate format, and DirectStorage 1.3, released in July 2025, introduced EnqueueRequests, giving developers greater control over how data requests are issued and synchronized with graphics work. Version 1.4 now builds on all of that with a more advanced compression format and a new preprocessing toolset that works before the game even ships.
Zstandard compression changes the rules for game data
The headline addition in DirectStorage 1.4 is native support for the Zstandard codec, commonly referred to as Zstd. Zstd is a popular, open compression standard that delivers competitive compression ratios and fast decompression performance, with broad availability across hardware and software platforms and widespread adoption in operating systems, cloud infrastructure, and web scenarios. Microsoft evaluated multiple codecs before landing on Zstd, citing its balance of compression efficiency, decompression speed, and existing industry adoption as the deciding factors.
In DirectStorage 1.4, Zstd is added to the multi-tier decompression framework with support for both CPU and GPU decompression paths, giving developers the flexibility to choose the best execution option depending on their workload. The previous GDeflate compression format introduced in DirectStorage 1.1 is not deprecated, Zstd becomes an additional supported option rather than a replacement, letting developers decide which format fits their pipeline best.
To support the rollout, Microsoft co-engineered DirectStorage 1.4 with GPU hardware vendors including AMD, Intel, NVIDIA, and Qualcomm, with driver updates from all four companies planned to deliver optimized Zstandard decompression performance across gaming hardware. AMD and NVIDIA have both confirmed their driver-level optimizations will arrive in the second half of 2026. Microsoft has also open-sourced its Zstd GPU decompression compute shader on the DirectStorage GitHub as a working baseline that all GPU implementations can reference and contribute to.
Beyond compression, DirectStorage 1.4 introduces global D3D12 CreatorID support to its EnqueueRequests function. This allows different GPU workloads to identify themselves to the driver, enabling smarter scheduling decisions when multiple queues are competing for GPU resources, which helps drivers better coordinate DirectStorage decompression work with traditional rendering and compute tasks, reducing the risk that asset streaming workloads interfere with frame rendering.
It is a technical addition, but one that could meaningfully improve real-world frame consistency in games that rely heavily on background asset loading.
GACL: Machine learning enters the asset pipeline
Alongside DirectStorage 1.4, Microsoft is releasing the public preview of the Game Asset Conditioning Library, a build-time tool designed to make game assets more compressible before they ever reach the player.
GACL works inside an existing content pipeline, reorganizing and transforming asset data using techniques like data shuffling and entropy reduction to improve how efficiently the data compresses with Zstd, while keeping runtime decompression costs low. Once the game is running, DirectStorage automatically reverses those transformations when the data is loaded, making the process transparent to the game engine.
Microsoft says GACL can deliver up to a 50% improvement in Zstd compression ratios for certain assets. To be precise, that figure refers to compression ratio improvement, not a guaranteed 50% reduction in total install size, but for texture-heavy assets, the gains can be significant, potentially resulting in much leaner game files without any noticeable loss in visual quality.
The library achieves this through Block-Level Entropy Reduction and Component-Level Entropy Reduction, with the latter using machine learning to guide the entropy reduction process at the component level. The current public preview supports BC1, BC3, BC4, and BC5 texture formats, with BC7 support planned for a future update. From the game engine’s perspective, the process is largely transparent, lowering the barrier to adoption and giving developers a way to optimize storage and streaming behavior without introducing major complexity into the rendering path.
What gamers can actually expect
For players, the impact of DirectStorage 1.4 will depend heavily on how quickly the development community integrates the new toolset. DirectStorage has had a somewhat underwhelming adoption run so far, despite early promises of dramatic improvements, only a handful of PC games have meaningfully implemented the technology. Ratchet & Clank: Rift Apart, Forza Motorsport, and Horizon Forbidden West are among the better-known examples, but the list remains short.
Part of what has held adoption back is a real technical tradeoff that version 1.4 is designed to address. GPU decompression is not free, when the GPU is spending time unpacking texture data, that is compute time it cannot spend on rendering frames. Because GPU time is typically the most precious resource in any modern game, the benefits of DirectStorage have historically depended on how much spare compute capacity a given system has. The CreatorID scheduling improvements in 1.4, combined with Zstd’s more efficient decompression overhead, are Microsoft’s answer to that problem.
If adopted at scale, the result would be faster loading times, smoother asset streaming, and smaller game files, a meaningful improvement across the board for both developers and players. For open-world titles that stream large amounts of data continuously, the benefits could be especially noticeable, potentially reducing texture pop-in and improving consistency during gameplay.
Ian LeGrow, Corporate Vice President of Windows and Devices at Microsoft, framed the company’s intent clearly: “This year at GDC, we’re introducing new Windows 11 platform updates and tools designed to deliver faster load times, smoother gameplay, and a strong foundation for Windows ML-enhanced graphics.” DirectStorage 1.4 fits squarely within that roadmap, and the involvement of all four major GPU vendors signals that Microsoft is building toward ecosystem-wide adoption rather than a limited rollout.
The technical benefits are real, Zstd compression, GPU-accelerated decompression, and machine learning-driven asset conditioning all address long-standing pain points in PC game development. The public preview of DirectStorage 1.4 and GACL is available now for developers, with the full impact expected to materialize as studios begin integrating the new tools into upcoming titles throughout 2026 and beyond.
Are you excited about what DirectStorage 1.4 could mean for the future of PC gaming, or do you think it’ll take years before we actually feel the difference? Tell us what you think in the comments!