Unlocking the Full Potential of the Cray XK 7 Accelerator

The Cray XK7 includes NVIDIA GPUs for acceleration of computing workloads, but the standard XK7 system software inhibits the GPUs from accelerating OpenGL and related graphics-specific functions. We have changed the operating mode of the XK7 GPU firmware, developed a custom X11 stack, and worked with Cray to acquire an alternate driver package from NVIDIA in order to allow users to render and post-process their data directly on Blue Waters. Users are able to use NVIDIA’s hardware OpenGL implementation which has many features not available in software rasterizers. By eliminating the transfer of data to external visualization clusters, time-to-solution for users has been improved tremendously. In one case, XK7 OpenGL rendering has cut turnaround time from a month down to to just one day. We describe our approach for enabling graphics on the XK7, discuss how the new capabilities are exposed to users, and highlight their use by science teams. Keywords-GPU computing; High-performance computing; Scientific visualization; Parallel rendering;