There are quite a few clever tricks to manage irregular problems. See poster: http://www.nvidia.com/content/GTC/posters/2010/A06-Task%20Management-for-Irregular

There are quite a few clever tricks to manage irregular problems. See poster: http://www.nvidia.com/content/GTC/posters/2010/A06-Task%20Management-for-Irregular-Workloads-on-the-GPU.pdf http://www.nvidia.com/content/GTC/posters/2010/A06-Task%20Ma... Also a presentation on OptiX shows how to implement ray tracer: http://www.nvidia.com/object/gtc2010-presentation-archive.html#session2250 http://www.nvidia.com/object/gtc2010-presentation-archive.ht... Ray-tracing could be done well on GPU (see OptiX), but it is not trivial and needs some tricks (persistant threads, work donation etc. which are not that common on CPUs)