FairRoot framework: GPUs for event reconstruction

In the last few years, the graphics processor units (GPUs) have moved away from the traditional fixed-function 3D graphics pipeline toward a flexible general-purpose computational engine. Moreover they are getting cheaper and more powerful [1]. The GPU is especially well-suited to address problems that can be expressed as data-parallel computations i.e. the same program is executed on many data elements in parallel. Because the same program is executed for each data element, there is a lower requirement for sophisticated flow control; and because it is executed on many data elements and has high arithmetic intensity, the memory access latency can be hidden with calculations instead of big data caches