Google's SwiftShader Is Becoming Conformant & Performant For Vulkan On CPUs

SwiftShader had traditionally been about OpenGL and Direct3D over CPUs as a fallback while in recent years Google has been focused on making it viable for Vulkan. Recently SwiftShader reached Vulkan 1.1 conformance, but besides being conformant to the standard it's also showing it has some CPU performance potential.

With Kazan (formerly known as Vulkan-CPU) not advancing too quickly, SwiftShader thanks to Google's resources is becoming quite competent for Vulkan atop CPUs. Google developer Nicolas Capens talked about SwiftShader in the context of Vulkan at this month's X.Org Developer's Conference in Montreal.

With Google being "all-in" on Vulkan, SwiftShader's support is necessary as a CPU fall-back and for cases like testing on GPU-less servers. With Android 10 is also "Project Pastel" as a CPU-based Vulkan 1.1 implementation but SwiftShader ultimately will be better and faster.

As for the performance, Google found that PowerVR's "Glass" Vulkan demo can run at over 30 FPS already on an Apple MacBook with SwiftShader. That is despite them having "no significant focus on performance yet", so ultimately things are looking good for SwiftShader as a CPU-based Vulkan implementation. Granted, it's a Vulkan tech demo, but not bad for purely CPU-based and likely more demanding that any basic Vulkan use-cases where one may be wanting a CPU fallback.

Those curious can learn a few more bits via this PDF slide deck from presenter Nicolas Capens.