One of the KDE GSoC contributors has been recently working on allowing the KStars astronomy application to tap OpenCL GPGPU support.
For what's been worked on so far, the new algorithm dealing with one million skypoints when using OpenCL takes only 30ms where as the old algorithm took 3947ms.
While OpenCL can provide some very important performance gains when dealing with a massive amount of data points as with KStars, the problem found is that the OpenCL support on Linux is still rather sad. This shouldn't come as a big surprise though for frequent Phoronix readers that the current Linux OpenCL support leaves a lot to be desired unless using the binary AMD/NVIDIA drivers. "The problem is that OpenCL support is still pretty flaky in terms of support – at the moment, there are three complete implementations that support Linux, by Intel, AMD, and nVidia respectively, and they’re all proprietary. There’s some promising work for the future with OpenCL in Mesa and also with [pocl] (an LLVM-based CPU-only implementation), but it’s not ready yet."
More details on the KStars OpenCL work can be found in this blog post.