@article{WendeMarsmanKimetal.2018, author = {Wende, Florian and Marsman, Martijn and Kim, Jeongnim and Vasilev, Fedor and Zhao, Zhengji and Steinke, Thomas}, title = {OpenMP in VASP: Threading and SIMD}, journal = {International Journal of Quantum Chemistry}, number = {Emerging Architectures in Computational Chemistry}, publisher = {Wiley Online Library}, doi = {10.1002/qua.25851}, pages = {e25851}, year = {2018}, abstract = {The Vienna Ab initio Simulation Package (VASP) is a widely used electronic structure code that originally exploits process-level parallelism through the Message Passing Interface (MPI) for work distribution within and across nodes. Architectural changes of modern parallel processors urge programmers to address thread- and data-level parallelism as well to benefit most from the available compute resources within a node. We describe for VASP how to approach for an MPI + OpenMP parallelization including data-level parallelism through OpenMP SIMD constructs together with a generic high-level vector coding scheme. We can demonstrate an improved scalability of VASP and more than 20\% gain over the MPI-only version, as well as a 2x increased performance of collective operations using the multiple-endpoint MPI feature. The high-level vector coding scheme applied to VASP's general gradient approximation routine gives up 9x performance gain on AVX512 platforms with the Intel compiler.}, language = {en} } @article{DickmannFalknerGuniaetal.2011, author = {Dickmann, Frank and Falkner, J{\"u}rgen and Gunia, Wilfried and Hampe, Jochen and Hausmann, Michael and Herrmann, Alexander and Kepper, Nick and Knoch, Tobias and Lauterbach, Svenja and Lippert, J{\"o}rg and Peter, Kathrin and Schmitt, Eberhard and Schwardmann, Ulrich and Solodenko, Juri and Sommerfeld, Dietmar and Steinke, Thomas and Weisbecker, Anette and Sax, Ulrich}, title = {Solutions for biomedical grid computing - Case studies from the D-Grid project Services@MediGRID}, volume = {-}, journal = {Journal of Computational Science}, number = {0}, doi = {10.1016/j.jocs.2011.06.006}, year = {2011}, language = {en} } @article{BirkenheuerBlunkBreuersetal.2011, author = {Birkenheuer, Georg and Blunk, Dirk and Breuers, Sebastian and Brinkmann, Andre and dos Santos Vieira, Ines and Fels, Gregor and Gesing, Sandra and Grunzke, Richard and Herres-Pawlis, Sonja and Kohlbacher, Oliver and Kr{\"u}ger, Jens and Lang, Ulrich and Packschies, Lars and M{\"u}ller-Pfefferkorn, Ralph and Sch{\"a}fer, Patrick and Schmalz, Hans-G{\"u}nther and Steinke, Thomas and Warzecha, Klaus Dieter and Wewior, Martin}, title = {A Molecular Simulation Grid as new tool for Computational Chemistry, Biology and Material Science}, volume = {3}, journal = {Journal of Cheminformatics 2011}, number = {Suppl 1}, doi = {10.1186/1758-2946-3-S1-P14}, year = {2011}, language = {en} } @article{GesingHerresPawlisBirkenheueretal.2012, author = {Gesing, Sandra and Herres-Pawlis, Sonja and Birkenheuer, Georg and Brinkmann, Andr{\´e} and Grunzke, Richard and Kacsuk, Peter and Kohlbacher, Oliver and Kozlovszky, Miklos and Kr{\"u}ger, Jens and M{\"u}ller-Pfefferkorn, Ralph and Sch{\"a}fer, Patrick and Steinke, Thomas}, title = {A Science Gateway Getting Ready for Serving the International Molecular Simulation Community}, volume = {PoS(EGICF12-EMITC2)050}, journal = {Proceedings of Science}, year = {2012}, language = {en} } @article{BirkenheuerBlunkBreuersetal.2012, author = {Birkenheuer, Georg and Blunk, Dirk and Breuers, Sebastian and Brinkmann, Andr{\´e} and dos Santos Vieira, Ines and Fels, Gregor and Gesing, Sandra and Grunzke, Richard and Herres-Pawlis, Sonja and Kohlbacher, Oliver and Kr{\"u}ger, Jens and Lang, Ulrich and Packschies, Lars and M{\"u}ller-Pfefferkorn, Ralph and Sch{\"a}fer, Patrick and Steinke, Thomas and Warzecha, Klaus Dieter and Wewior, Martin}, title = {MoSGrid: efficient data management and a standardized data exchange format for molecular simulations in a grid environment}, volume = {4}, journal = {Journal of Cheminformatics}, number = {Suppl 1}, doi = {10.1186/1758-2946-4-S1-P21}, pages = {21}, year = {2012}, language = {en} } @article{GesingGrunzkeKruegeretal.2012, author = {Gesing, Sandra and Grunzke, Richard and Kr{\"u}ger, Jens and Birkenheuer, Georg and Wewior, Martin and Sch{\"a}fer, Patrick and Schuller, Bernd and Schuster, Johannes and Herres-Pawlis, Sonja and Breuers, Sebastian and Balasko, Akos and Kozlovszky, Miklos and Szikszay Fabri, Anna and Packschies, Lars and Kacsuk, Peter and Blunk, Dirk and Steinke, Thomas and Brinkmann, Andr{\´e} and Fels, Gregor and M{\"u}ller-Pfefferkorn, Ralph and J{\"a}kel, Ren{\´e} and Kohlbacher, Oliver}, title = {A Single Sign-On Infrastructure for Science Gateways on a Use Case for Structural Bioinformatics}, journal = {Journal of Grid Computing}, year = {2012}, language = {en} } @article{DresslerSteinke2012, author = {Dreßler, Sebastian and Steinke, Thomas}, title = {Energy consumption of CUDA kernels with varying thread topology}, journal = {Computer Science - Research and Development}, publisher = {Springer Berlin / Heidelberg}, doi = {10.1007/s00450-012-0230-4}, pages = {1 -- 9}, year = {2012}, language = {en} } @article{AlhaddadFoerstnerGrothetal.2021, author = {Alhaddad, Samer and F{\"o}rstner, Jens and Groth, Stefan and Gr{\"u}newald, Daniel and Grynko, Yevgen and Hannig, Frank and Kenter, Tobias and Pfreundt, Franz-Josef and Plessl, Christian and Schotte, Merlind and Steinke, Thomas and Teich, J{\"u}rgen and Weiser, Martin and Wende, Florian}, title = {HighPerMeshes - A Domain-Specific Language for Numerical Algorithms on Unstructured Grids}, journal = {Euro-Par 2020: Parallel Processing Workshops.}, publisher = {Springer}, doi = {10.1007/978-3-030-71593-9_15}, pages = {185 -- 196}, year = {2021}, abstract = {Solving partial differential equations on unstructured grids is a cornerstone of engineering and scientific computing. Nowadays, heterogeneous parallel platforms with CPUs, GPUs, and FPGAs enable energy-efficient and computationally demanding simulations. We developed the HighPerMeshes C++-embedded Domain-Specific Language (DSL) for bridging the abstraction gap between the mathematical and algorithmic formulation of mesh-based algorithms for PDE problems on the one hand and an increasing number of heterogeneous platforms with their different parallel programming and runtime models on the other hand. Thus, the HighPerMeshes DSL aims at higher productivity in the code development process for multiple target platforms. We introduce the concepts as well as the basic structure of the HighPer-Meshes DSL, and demonstrate its usage with three examples, a Poisson and monodomain problem, respectively, solved by the continuous finite element method, and the discontinuous Galerkin method for Maxwell's equation. The mapping of the abstract algorithmic description onto parallel hardware, including distributed memory compute clusters is presented. Finally, the achievable performance and scalability are demonstrated for a typical example problem on a multi-core CPU cluster.}, language = {en} } @article{KnoopGronemeierSuehringetal.2017, author = {Knoop, Helge and Gronemeier, Tobias and S{\"u}hring, Matthias and Steinbach, Peter and Noack, Matthias and Wende, Florian and Steinke, Thomas and Knigge, Christoph and Raasch, Siegfried and Ketelsen, Klaus}, title = {Porting the MPI-parallelized LES model PALM to multi-GPU systems and many integrated core processors: an experience report}, journal = {International Journal of Computational Science and Engineering. Special Issue on: Novel Strategies for Programming Accelerators}, edition = {Special Issue on: Novel Strategies for Programming Accelerators}, publisher = {Inderscience}, year = {2017}, abstract = {The computational power and availability of graphics processing units (GPUs), such as the Nvidia Tesla, and Many Integrated Core (MIC) processors, such as the Intel Xeon Phi, on high performance computing (HPC) systems is rapidly evolving. However, HPC applications need to be ported to take advantage of such hardware. This paper is a report on our experience of porting the MPI+OpenMP parallelised large-eddy simulation model (PALM) to multi-GPU as well as to MIC processor environments using the directive-based high level programming paradigm OpenACC and OpenMP, respectively. PALM is a Fortran-based computational fluid dynamics software package, used for the simulation of atmospheric and oceanic boundary layers to answer questions linked to fundamental atmospheric turbulence research, urban modelling, aircraft safety and cloud physics. Development of PALM started in 1997, the project currently entails 140 kLOC and is used on HPC farms of up to 43,200 cores. The main challenges we faced during the porting process are the size and complexity of the PALM code base, its inconsistent modularisation and the complete lack of a unit-test suite. We report the methods used to identify performance issues as well as our experiences with state-of-the-art profiling tools. Moreover, we outline the required porting steps in order to properly execute our code on GPUs and MIC processors, describe the problems and bottlenecks that we encountered during the porting process, and present separate performance tests for both architectures. These performance tests, however, do not provide any benchmark information that compares the performance of the ported code between the two architectures.}, language = {en} } @article{MayKreuchwigSteinkeetal.2010, author = {May, Patrick and Kreuchwig, A. and Steinke, Thomas and Koch, Ina}, title = {PTGL: a database for secondary structure-based protein topologies}, volume = {38}, journal = {Nucleic Acids Res.}, pages = {D326 -- 330}, year = {2010}, language = {en} }