A new test application written using the ATI OpenCL SDK called SmallptGPU shows path-tracing, an optimized variation of ray tracing, shows the impressive performance of ATI cards. The demonstration video below is running on the Radeon 4870, with impressive results, but the newer 5970 should be at least 4x faster. Also, the OpenCL renderer will automatically take advantage and scale across as many cards as you can install in your system.
See the demonstration video after the break.
OpenCL path tracer / ray tracing demo using the AMD OpenCL Beta SDK | FireUser Blog.
