v136 · miscellaneous

WebGPU: GPUAdapterInfo isFallbackAdapter attribute

Functionality added to the WebGPU spec after its first shipment in a browser. The GPUAdapterInfo isFallbackAdapter boolean attribute indicates if an adapter has significant performance limitations in return for wider compatibility, more predictable behavior, and/or improved privacy. Note that a fallback adapter may not be present on all systems.

concepts

  1. GPUAdapterInfo.isFallbackAdapter

    GPUAdapterInfo gains an isFallbackAdapter attribute, replacing the old adapter-level flag. Cleaner home for the info.

  2. Library-side detect

    The chromestatus motivation: a library given a pre-built GPUDevice reads device.adapterInfo.isFallbackAdapter to decide between compute and CPU paths — the access point that didn't exist before.

  3. Adapter Strategy

    Three real-world strategies — GPU-only, prefer high-perf, CPU twin — each driving requestAdapter()/requestDevice() and using both adapter.info and device.adapterInfo to make a decision.

  4. Fallback Workload Planner

    Reads device.adapterInfo.isFallbackAdapter and routes a table of compute tasks — particle workload, matrix multiply, image convolution — to GPU or CPU paths based on whether the adapter is a software fallback. Use adapter override controls to preview routing changes.

why it shipped

The GPUAdapter isFallbackAdapter boolean attribute currently shipped in Chrome browser only does not allow libraries that take user-provided GPUDevice objects from accessing this information through the adapterInfo attribute on GPUDevice. Adding a GPUAdapterInfo isFallbackAdapter boolean attribute solves this problem.

references