CUDA Ray Tracing 2x Faster Than RTX: My CUDA Ray Tracing Journey
10 months ago
- #CUDA
- #Performance Optimization
- #Ray Tracing
- CUDA-based ray tracer outperforms Vulkan/RTX implementation by 2x on the same hardware.
- Optimizations include aggressive inlining, killing recursion with an explicit stack, and precomputing known values.
- Structure of Arrays (SoA) layout improves memory access patterns and reduces cache misses.
- Alignment and cacheline efficiency optimizations significantly reduce global memory requests.
- Using constant memory for read-only parameters reduces register pressure and improves caching.
- Branchless material sampling and evaluation minimizes warp divergence.
- Custom RNG implementation outperforms CUDA's curand library in performance-critical paths.
- Direct CUDA→OpenGL texture mapping bypasses CPU staging, reducing latency.
- Benchmarks show CUDA implementation running up to 50x faster than CPU-only versions at higher resolutions.
- Future work includes wavefront path tracing, triangle support, and OptiX backend integration.