TY  - CONF
AU  - Fabregat-Traver, Diego
AU  - Davidović, Davor
AU  - Höhnerbach, Markus
AU  - Di Napoli, Edoardo
TI  - Hybrid CPU-GPU generation of the Hamiltonian and Overlap matrices in FLAPW methods
VL  - 10164
PB  - Springer-Verlag
M1  - FZJ-2016-05749
T2  - Lecture Notes in Computer Science
SP  - 200-211
PY  - 2016
AB  - In this paper we focus on the integration of high-performance numerical libraries in ab initio codes and the portability of performance and scalability. The target of our work is FLEUR, a software for electronic structure calculations developed in the Forschungszentrum J\'ulich over the course of two decades. The presented work follows up on a previous effort to modernize legacy code by re-engineering and rewriting it in terms of highly optimized libraries. We illustrate how this initial effort to get efficient and portable shared-memory code enables fast porting of the code to emerging heterogeneous architectures. More specifically, we port the code to nodes equipped with multiple GPUs. We divide our study in two parts. First, we show considerable speedups attained by minor and relatively straightforward code changes to off-load parts of the computation to the GPUs. Then, we identify further possible improvements to achieve even higher performance and scalability. On a system consisting of 16-cores and 2 GPUs, we observe speedups of up to 5x with respect to our optimized shared-memory code, which in turn means between 7.5x and 12.5x speedup with respect to the original FLEUR code.
T2  - JARA High-Performance Computing Symposium
CY  - 4 Oct 2016 - 5 Oct 2016, Aachen (Germany)
Y2  - 4 Oct 2016 - 5 Oct 2016
M2  - Aachen, Germany
LB  - PUB:(DE-HGF)8 ; PUB:(DE-HGF)7
DO  - DOI:10.1007/978-3-319-53862-4_17
UR  - https://juser.fz-juelich.de/record/820439
ER  -