Valve's open-source Linux graphics team has landed a new debugging GUI in Mesa 26.1 aimed squarely at squeezing more Vulkan ray-tracing performance out of AMD Radeon hardware. Called the Ray-Tracing Inspector (RTI), the tool lets driver developers crack open and analyze the acceleration structures and ray dispatches that the RADV driver feeds the GPU, the same code path that powers ray tracing for Steam Play and native Linux titles.
Written by Konstantin Seurer, RTI is built on Dear ImGui with Vulkan and SDL3 backends, reusing existing RADV debug plumbing. The workflow is straightforward: set RADV_DEBUG=rti and the driver dumps its internal BVH and ray history data to an RTI file in /tmp, which the GUI then loads for inspection of the bounding volume hierarchy and individual RT dispatches. It compiles via the -D tools=rti Meson option. This is strictly developer tooling, not an end-user feature, and while it starts with RADV, its back-end design leaves room to target other drivers and hardware later.
RTI arrives on top of a steady run of RADV ray-tracing gains. Mesa 26.0, released on 2026-02-11, switched RT shaders on RDNA3 and RDNA4 to Wave32 execution and reworked launch ID swizzling, work led by Valve's Natalie Vock that delivered roughly a 4x to 8x speedup in Unreal Engine 5's hardware Lumen passes for around a 30 percent total framerate gain in affected scenes. A purpose-built inspector for the BVH and dispatch internals is the logical next step toward chasing down the remaining bottlenecks, and the kind of tooling that makes those optimizations repeatable rather than one-off.
The full merge request is now part of Mesa 26.1, which is tracking toward a stable release in the coming weeks. Mesa is free software, so anyone running a recent RADV build can pull the tree and compile RTI today.