NVIDIA RTXPT 1.9 Path Tracer Gets Around 20% Faster, Adds Windows on Arm Support

What happened

NVIDIA has released version 1.9.0 of RTX Path Tracing (RTXPT), its open-source reference path tracer on GitHub , claiming roughly 20% better performance than the previous 1.8.1 release, with comparable or better image quality. RTXPT is a code sample for developers, meant as a starting point for building a path tracer or as a reference for NVIDIA's other ray tracing SDKs (the toolkit a developer builds on a platform with). NVIDIA is a semiconductor company based in Santa Clara, and its products and services include graphics processing units.

Several changes add up to that uplift. The path tracer can now optionally trace only three quarters, half, or a quarter of the pixels each frame, and the built-in performance presets use this by default, along with lower bounce limits in the faster modes.

On DirectX 12, async compute lets the previous frame's DLSS Ray Reconstruction and post-processing overlap with the next frame's path tracing, and TLAS instance generation has moved to the GPU. The release notes don't say why, though it's probably no coincidence, given NVIDIA's own Arm-based RTX Spark chip for Windows PCs.