scholarly journals Locality properties of 3D data orderings with application to parallel molecular dynamics simulations

2019 ◽  
Vol 33 (5) ◽  
pp. 998-1018
Author(s):  
Ibrahim Al-Kharusi ◽  
David W Walker
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Spatial Data ◽  
Data Locality ◽  
Data Reuse ◽  
Dynamic Simulations ◽  
Data Movement ◽  
Execution Speed ◽  
Dynamics Simulations ◽  
The Impact

Application performance on graphical processing units (GPUs), in terms of execution speed and memory usage, depends on the efficient use of hierarchical memory. It is expected that enhancing data locality in molecular dynamic simulations will lower the cost of data movement across the GPU memory hierarchy. The work presented in this article analyses the spatial data locality and data reuse characteristics for row-major, Hilbert and Morton orderings and the impact these have on the performance of molecular dynamics simulations. A simple cache model is presented, and this is found to give results that are consistent with the timing results for the particle force computation obtained on NVidia GeForce GTX960 and Tesla P100 GPUs. Further analysis of the observed memory use, in terms of cache hits and the number of memory transactions, provides a more detailed explanation of execution behaviour for the different orderings. To the best of our knowledge, this is the first study to investigate memory analysis and data locality issues for molecular dynamics simulations of Lennard-Jones fluids on NVidia’s Maxwell and Tesla architectures.

scholarly journals Exploiting correlated molecular-dynamics networks to counteract enzyme activity–stability trade-off

2018 ◽  
Vol 115 (52) ◽  
pp. E12192-E12200 ◽  
Author(s):  
Haoran Yu ◽  
Paul A. Dalby
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Active Site ◽  
Dynamic Networks ◽  
Aromatic Aldehydes ◽  
Active Site Residues ◽  
Trade Off ◽  
Highly Correlated ◽  
Dynamics Simulations ◽  
The Impact

The directed evolution of enzymes for improved activity or substrate specificity commonly leads to a trade-off in stability. We have identified an activity–stability trade-off and a loss in unfolding cooperativity for a variant (3M) of Escherichia coli transketolase (TK) engineered to accept aromatic substrates. Molecular dynamics simulations of 3M revealed increased flexibility in several interconnected active-site regions that also form part of the dimer interface. Mutating the newly flexible active-site residues to regain stability risked losing the new activity. We hypothesized that stabilizing mutations could be targeted to residues outside of the active site, whose dynamics were correlated with the newly flexible active-site residues. We previously stabilized WT TK by targeting mutations to highly flexible regions. These regions were much less flexible in 3M and would not have been selected a priori as targets using the same strategy based on flexibility alone. However, their dynamics were highly correlated with the newly flexible active-site regions of 3M. Introducing the previous mutations into 3M reestablished the WT level of stability and unfolding cooperativity, giving a 10.8-fold improved half-life at 55 °C, and increased midpoint and aggregation onset temperatures by 3 °C and 4.3 °C, respectively. Even the activity toward aromatic aldehydes increased up to threefold. Molecular dynamics simulations confirmed that the mutations rigidified the active-site via the correlated network. This work provides insights into the impact of rigidifying mutations within highly correlated dynamic networks that could also be useful for developing improved computational protein engineering strategies.

Conformational and aggregation properties of PffBT4T polymers: atomistic insight into the impact of alkyl-chain branching positions

2019 ◽  
Vol 7 (45) ◽  
pp. 14198-14204
Author(s):  
Lu Ning ◽  
Guangchao Han ◽  
Yuanping Yi
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Alkyl Chain ◽  
Temperature Dependent ◽  
Chain Branching ◽  
Alkyl Chains ◽  
Dynamics Simulations ◽  
The Impact ◽  
Insight Into

The impact of the branching positions of alkyl chains on temperature dependent aggregation is rationalized by atomistic molecular dynamics simulations.

Water structures on a Pt(111) electrode from ab initio molecular dynamic simulations for a variety of electrochemical conditions

2020 ◽  
Vol 22 (19) ◽  
pp. 10431-10437 ◽  
Author(s):  
Sung Sakong ◽  
Axel Groß
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Molecular Dynamics Simulations ◽  
Molecular Dynamic ◽  
Metal Electrode ◽  
Molecular Dynamic Simulations ◽  
Dynamic Simulations ◽  
Dynamics Simulations

Water structures on a Pt(111) metal electrode critically depend on the electrochemical conditions, as shown by ab initio molecular dynamics simulations.

scholarly journals Impact of deep eutectic solvents (DESs) and individual DES components on alcohol dehydrogenase catalysis: Connecting experimental data and molecular dynamics simulations

2021 ◽  
Author(s):  
Jan Philipp Bittner ◽  
Ningning Zhang ◽  
Lei Huang ◽  
Pablo Dominguez de Maria ◽  
Sven Jakobtorweihen ◽  
...  
Keyword(s):  
Experimental Data ◽  
Molecular Dynamics ◽  
Alcohol Dehydrogenase ◽  
Molecular Dynamics Simulations ◽  
Enzyme Catalysis ◽  
Deep Eutectic Solvents ◽  
Knowledge Based ◽  
Dynamics Simulations ◽  
The Impact ◽  
Knowledge Based Design

For a knowledge-based design of enzyme catalysis in deep eutectic solvents (DESs), the influence of the DESs properties (e.g., water activity, viscosity), and the impact of DESs and their individual...

Dielectric relaxation of water: assessing the impact of localized modes, translational diffusion, and collective dynamics

2021 ◽  
Vol 23 (37) ◽  
pp. 20875-20882
Author(s):  
Christoph Hölzl ◽  
Harald Forbert ◽  
Dominik Marx
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Dielectric Relaxation ◽  
Molecular Dynamics Simulations ◽  
Relaxation Spectrum ◽  
Translational Diffusion ◽  
Localized Modes ◽  
Collective Dynamics ◽  
Dynamics Simulations ◽  
The Impact

The dielectric relaxation spectrum of water can be quantitatively reproduced by ab initio molecular dynamics simulations. Its decomposition into auto- and crosscorrelation terms suggests that fits of experimental spectra may require revision.

Mix and Match: Reorganizing Tasks for Enhancing Data Locality

2021 ◽  
Vol 5 (2) ◽  
pp. 1-24
Author(s):  
Xulong Tang ◽  
Mahmut Taylan Kandemir ◽  
Mustafa Karakoy
Keyword(s):  
Spatial Data ◽  
State Of The Art ◽  
Data Access ◽  
Data Locality ◽  
Data Reuse ◽  
Large Set ◽  
Data Movement ◽  
High Data ◽  
Multithreaded Programs ◽  
Data Location

Application programs that exhibit strong locality of reference lead to minimized cache misses and better performance in different architectures. However, to maximize the performance of multithreaded applications running on emerging manycore systems, data movement in on-chip network should also be minimized. Unfortunately, the way many multithreaded programs are written does not lend itself well to minimal data movement. Motivated by this observation, in this paper, we target task-based programs (which cover a large set of available multithreaded programs), and propose a novel compiler-based approach that consists of four complementary steps. First, we partition the original tasks in the target application into sub-tasks and build a data reuse graph at a sub-task granularity. Second, based on the intensity of temporal and spatial data reuses among sub-tasks, we generate new tasks where each such (new) task includes a set of sub-tasks that exhibit high data reuse among them. Third, we assign the newly-generated tasks to cores in an architecture-aware fashion with the knowledge of data location. Finally, we re-schedule the execution order of sub-tasks within new tasks such that sub-tasks that belong to different tasks but share data among them are executed in close proximity in time. The detailed experiments show that, when targeting a state of the art manycore system, our proposed compiler-based approach improves the performance of 10 multithreaded programs by 23.4% on average, and it also outperforms two state-of-the-art data access optimizations for all the benchmarks tested. Our results also show that the proposed approach i) improves the performance of multiprogrammed workloads, and ii) generates results that are close to maximum savings that could be achieved with perfect profiling information. Overall, our experimental results emphasize the importance of dividing an original set of tasks of an application into sub-tasks and constructing new tasks from the resulting sub-tasks in a data movement- and locality-aware fashion.

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