Today we’re proud to announce a landmark achievement for the Vulkan ecosystem: KosmicKrisp, LunarG’s Vulkan-to-Metal driver for Apple Silicon, has passed the Vulkan Conformance Test Suite (CTS), a rigorous, Khronos-mandated benchmark of API correctness. Thus, KosmicKrisp is now a Khronos Vulkan conformant product for Vulkan 1.3. This isn’t a portability layer with caveats. This is a spec-compliant Vulkan 1.3 running natively on macOS 15+ via Metal — achieved in just 10 months from the start of the project.
What This Means
For the first time, Apple Silicon GPUs (M1, M2, M3, and beyond) can run Vulkan 1.3 applications without “Vulkan Portability” compromises. This is a critical foundation: it proves that the driver adheres to the Vulkan 1.3 specification across core functionality, synchronization, resource management, and shader execution.
Vulkan is now truly cross-platform — including macOS. Let’s build the future!
Why This Matters
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Real cross-platform portability on macOS without special shims
Passing conformance means KosmicKrisp implements the Vulkan contract the same way drivers on Windows/Linux do. That lets developers target Vulkan 1.3 directly on Apple Silicon without relying on portability layers — improving portability and reducing platform-specific code paths. KosmicKrisp eliminates the need for separate “Vulkan Portability” solutions on Apple silicon. -
Predictable shader and rendering behavior
CTS-verified shader correctness, pipeline semantics, and dynamic rendering support along with GPU-accelerated rendering means that developers can expect the same rendering results across all major platforms. That reduces platform-specific debugging time and makes automated testing (CI) more trustworthy. -
Confidence for tooling and middleware
Tools (profilers, debuggers, validation layers, game engines, emulators) depend on a correct implementation to behave as expected. For example, the Android Emulator and other tooling that relies on Vulkan can target macOS with higher confidence if the driver is conformant. -
Easier QA and certification for cross-platform titles
Studios and ISVs that must certify behavior across target platforms now have a trusted, spec-compliant baseline on macOS — making release planning and QA more straightforward.
The Journey: 10 Months to Conformance
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Milestone
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Date
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Project Kickoff
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November 2024
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First compute tests pass
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February 2025
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First triangle
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March 2025
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To get a deeper understanding of KosmicKrisp and what it means to the industry, check out Aitor’s recent talk on KosmicKrisp at XDC 2025 here.
What’s Next
Passing the Vulkan 1.3 CTS confirms core API correctness. KosmicKrisp has been upstreamed to Mesa and will be added to the macOS Vulkan SDK alongside MoltenVK in the near future.
However, conformance does not guarantee application compatibility — real apps often rely on optional extensions, undefined tolerances, or vendor-specific behavior not covered by the test suite. That’s why we’re now rigorously testing actual workloads (games, engines, compute frameworks) to catch and fix additional issues. Conformance is the baseline; application testing is the proof.
Thank You Google!
This milestone would not have been possible without the partnership of Google.From day one, Google’s Android and Chrome OS teams championed the goal of native, conformant Vulkan on Apple Silicon—not just for emulation, but for a truly cross-platform future.
