Bone structure analysis on multiple GPGPUs

• Highly efficient finite element analysis of bone structure.
• Element-by-element sparse matrix multiplication.
• Solution of problems in linear elasticity with up to 25 billion degrees of freedom.
• Scalability analyses on a Cray XK7 with up to 256 NVIDIA Tesla K20X GPUs.
• GPU optimizations speed up the CPU performance by more than 30%.

Osteoporosis is a disease that affects a growing number of people by increasing the fragility of their bones. To improve the understanding of the bone quality, large scale computer simulations are applied. A fast, scalable and memory efficient solver for such problems is ParOSol. It uses the preconditioned conjugate gradient algorithm with a multigrid preconditioner. A modification of ParOSol is presented that profits from the exorbitant compute capabilities of recent general-purpose graphics processing units (GPGPUs). Adaptations of data structures for the GPGPU are discussed. The fastest implementation on a GPGPU achieves a speedup of more than five compared with the CPU implementation and scales from 1 to at least 256 GPGPUs.