# Parallelization of a dynamic Monte Carlo algorithm: A partially rejection-free conservative approach

## Abstract

The authors experiment with a massively parallel implementation of an algorithm for simulating the dynamics of metastable decay in kinetic Ising models. The parallel scheme is directly applicable to a wide range of stochastic cellular automata where the discrete events (updates) are Poisson arrivals. For high performance, they utilize a continuous-time, asynchronous parallel version of the n-fold way rejection-free algorithm. Each processing element carries an l {times} l block of spins, and they employ fast one-sided communication routines on a distributed-memory parallel architecture. Different processing elements have different local simulated times. To ensure causality, the algorithm handles the asynchrony in a conservative fashion. Despite relatively low utilization and an intricate relationship between the average time increment and the size of the spin blocks, they find that the algorithm is scalable and for sufficiently large l it outperforms its corresponding parallel Metropolis (non-rejection-fee) counterpart. As a sample application, they present results for metastable decay in a model ferromagnetic or ferroelectric film, observed with a probe of area smaller than the total system.

- Authors:

- Florida State Univ., Tallahassee, FL (United States)

- Publication Date:

- Sponsoring Org.:
- USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)

- OSTI Identifier:
- 687483

- DOE Contract Number:
- FG02-85ER25000; AC03-76SF00098

- Resource Type:
- Journal Article

- Journal Name:
- Journal of Computational Physics

- Additional Journal Information:
- Journal Volume: 153; Journal Issue: 2; Other Information: PBD: 10 Aug 1999

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 99 MATHEMATICS, COMPUTERS, INFORMATION SCIENCE, MANAGEMENT, LAW, MISCELLANEOUS; 66 PHYSICS; ALGORITHMS; MONTE CARLO METHOD; PARALLEL PROCESSING; ISING MODEL; STOCHASTIC PROCESSES; COMPUTER ARCHITECTURE; FERROMAGNETIC MATERIALS; FERROELECTRIC MATERIALS

### Citation Formats

```
Korniss, G., Novotny, M.A., and Rikvold, P.A.
```*Parallelization of a dynamic Monte Carlo algorithm: A partially rejection-free conservative approach*. United States: N. p., 1999.
Web. doi:10.1006/jcph.1999.6291.

```
Korniss, G., Novotny, M.A., & Rikvold, P.A.
```*Parallelization of a dynamic Monte Carlo algorithm: A partially rejection-free conservative approach*. United States. doi:10.1006/jcph.1999.6291.

```
Korniss, G., Novotny, M.A., and Rikvold, P.A. Tue .
"Parallelization of a dynamic Monte Carlo algorithm: A partially rejection-free conservative approach". United States. doi:10.1006/jcph.1999.6291.
```

```
@article{osti_687483,
```

title = {Parallelization of a dynamic Monte Carlo algorithm: A partially rejection-free conservative approach},

author = {Korniss, G. and Novotny, M.A. and Rikvold, P.A.},

abstractNote = {The authors experiment with a massively parallel implementation of an algorithm for simulating the dynamics of metastable decay in kinetic Ising models. The parallel scheme is directly applicable to a wide range of stochastic cellular automata where the discrete events (updates) are Poisson arrivals. For high performance, they utilize a continuous-time, asynchronous parallel version of the n-fold way rejection-free algorithm. Each processing element carries an l {times} l block of spins, and they employ fast one-sided communication routines on a distributed-memory parallel architecture. Different processing elements have different local simulated times. To ensure causality, the algorithm handles the asynchrony in a conservative fashion. Despite relatively low utilization and an intricate relationship between the average time increment and the size of the spin blocks, they find that the algorithm is scalable and for sufficiently large l it outperforms its corresponding parallel Metropolis (non-rejection-fee) counterpart. As a sample application, they present results for metastable decay in a model ferromagnetic or ferroelectric film, observed with a probe of area smaller than the total system.},

doi = {10.1006/jcph.1999.6291},

journal = {Journal of Computational Physics},

number = 2,

volume = 153,

place = {United States},

year = {1999},

month = {8}

}