ratGPU is a new OpenCL ray tracer. Currently there are two versions of ratGPU: standalone (the one I tested) and 3ds Max 2010/2011 plugins. ratGPU is free and is available for Windows and Linux (Ubuntu 10.04 / 10.10).
I quickly tested ratGPU on my GTX 460 + R260.93 and it worked perfectly. You can save the rendering to an image (*.png). There’s also a benchmarking mode (click on the top-left graph button) but it lasts too long for me so I stopped it after 2 minutes… Try it and post your scores in the comments.
The standalone renderer comes with 4 demos scenes that have been created (I suppose) with the 3ds Max plugin.
And for ATI / NVIDIA fanboys, this short passage:
Although I spent a lot of time optimizing for ATI cards, they seem to be not able to catch NVIDIA’s OpenCL performance with the current implementation.
Example of a benchmark score