Stay up-to-date with the OpenACC Monthly Highlights. February's edition covers the updated specification OpenACC 3.2, upcoming GPU Hackathons and Bootcamps, OpenACC's BOF at SC21 , recent research, new resources and more!

1. February 2022
OPENACC MONTHLY
HIGHLIGHTS

2. 2
WHAT IS OPENACC?
main()
{
<serial code>
#pragma acc kernels
{
<parallel code>
}
}
Add Simple Compiler Directive
POWERFUL & PORTABLE
Directives-based
programming model for
parallel
computing
Designed for
performance and
portability on
CPUs and GPUs
SIMPLE
Open Specification Developed by OpenACC Organization

3. 3
silica IFPEN, RMM-DIIS on P100
OPENACC GROWING MOMENTUM
Wide Adoption Across Key HPC Codes
ANSYS Fluent
Gaussian
VASP
LSDalton
MPAS
GAMERA
GTC
XGC
ACME
FLASH
COSMO
Numeca
230+ APPS* USING OpenACC
Prof. Georg Kresse
Computational Materials Physics
University of Vienna
For VASP, OpenACC is the way forward for GPU
acceleration. Performance is similar to CUDA, and
OpenACC dramatically decreases GPU
development and maintenance efforts. We’re
excited to collaborate with NVIDIA and PGI as an
early adopter of Unified Memory.
“ “
VASP
Top Quantum Chemistry and Material Science Code
* Applications in production and development

4. 4
LEARN MORE
The development work for OpenACC 3.2 focused primarily
on the addition of an error handler API, to enable
developers and tools to register an error handler routine,
which can then run to gracefully shut down the application
and potentially save state to help diagnose the error.
Other additions include the addition of “wait any” routines
in the runtie API, ability to use async clause on data
constructs, many clarifications and reorganizations, as
well as LLVM upstreaming.
UPDATED SPECIFICATION: OPENACC 3.2
NOW AVAILABLE

5. 5
UPCOMING GPU BOOTCAMP & HACKATHONS
COMPLETE LIST OF EVENTS
Event Call Closes Event Date
Indonesia AI Nation: Introduction to Artificial Intelligence Bootcamp March 13, 2022 March 24-25, 2022
NSM India CFD GPU Bootcamp March 19, 2022 March 29-31, 2022
CALMIP Multi-GPU Programming Bootcamp March 16, 2022 April 4-5, 2022
NCC Portugal N-Ways to GPU Programming Bootcamp March 29, 2022 April 13-14, 2022
San Diego Supercomputer Center (SDSC) GPU Hackathon 2022 March 13, 2022 May 3, 10-12, 2022
IDRIS GPU Hackathon 2022 March 31, 2022 May 9, 17-19, 2022
KISTI N-Ways to GPU Programming Bootcamp 2022 May 10, 2022 May 16-18, 2022
MPCDF AI for Science Bootcamp May 9, 2022 May 23-24, 2022
Princeton GPU Hackathon 2022 April 13, 2022 June 1, 7-9, 2022
Digital in 2022: Our virtual events continue to offer the same high-touch training and mentorship without the
hassle of travel!

6. 6
READ THE BLOG
In a collaboration between OpenACC, the
National Center for High-Performance
Computing, Taiwan Web Service Corporation,
and NVIDIA, the recent TWCC GPU Hackathon
acted as a catalyst for developers and engineers
to advance their AI and HPC projects using
GPUs.
12 teams used approaches to accelerate projects
ranging from an AI-driven manufacturing
scheduling model to rapid flood prediction.
GPU HACKATHON OPTIMIZES MODELING
RESULTS

7. 7
REGISTER NOW
Learn from some of the world’s brightest minds. Connect with
experts. Network with your peers. And discover the
technological advancements and groundbreaking research
that are making it possible to take on the world’s greatest
challenges—together.
GTC is all about four days of discovery. Come explore what’s
driving transformation in your field.
Join us in March at this virtual conference and discover how
to accelerate your life’s work. Registration is FREE!
YOUR MOST BRILLIANT WORK STARTS HERE
NVIDIA GTC 2022

8. 8
WATCH ON-DEMAND VIDEOS
OpenACC’s Birds-of-a-Feather (BOF) interactive discussion at
SC21 invited programmers and researchers to learn about the
roadmaps and latest developments in the language specification
and discuss their experiences in adopting OpenACC for scientific
applications.
Presenters included:
CATCH UP ON SC21: OPENACC BOF
AVAILABLE NOW
Jack Wells, OpenACC President
Jeff Larkin, OpenACC Technical Committee Co-Chair
John Levesque, HPE
Thomas Schwinge, Siemens
Stéphane Ethier, Princeton Plasma Physics Laboratory (PPPL)
Ron Caplan, Predictive Science LLC
Julia Levites, OpenACC Marketing Committee Chair

9. 9
RESOURCES
Paper: High Resolution of City-Level Climate Simulation by GPU
with Multi-physical Phenomena
Koei Watanabe, Kohei Kikuchi, Taisuke Boku, Takuto Sato, and Hiroyuki Kusaka
In this paper, we describe the Graphics Processing unit (GPU) implementation of our
City-LES code on detailed large eddy simulations, including the multi-physical
phenomena on fluid dynamics, heat absorption and reflection by surface and building
material, cloud effects, and even sunlight effect. Because a detailed simulation involving
these phenomena is required for analyses at the street level and several meters of
resolution, the computation amount is enormous and ordinary CPU computation cannot
provide sufficient performance. Therefore, we implemented the entire code on GPU
clusters with large-scale computing. We applied OpenACC coding to incrementally
implement relatively easy programing and eliminate data transfers between the CPU
and GPU memories. Based on this research, we determined that the elimination of data
transfers is effective, even in the case where a part of the code execution on the PU Is
slower than the CPU, owing to the absences of spatial parallelism. The objective of this
study is to perform a complete climate simulation on a few square-kilometers field
around the Tokyo Station, considering the finest resolution of the original highlighted
area of the Marathon race in the Olympic Games Tokyo 2020. We successfully
transferred the entire code to the GPU to provide approximately eight times the
performance of CPU-only computation on multi-GPU per node with a large scale
cluster.
READ PAPER Fig. 1: Simulation result image of City-LES

10. 10
RESOURCES
Paper: Paper: OpenACC Acceleration of an Agent-Based Biological
Simulation Framework
Matthew Stack, Paul Macklin, Robert Searles, and Sunita Chandrasekaran
Computational biology has increasingly turned to agent-based modeling to
explore complex biological systems. Biological diffusion (diffusion, decay,
secretion, and uptake) is a key driver of biological tissues. GPU computing can
vastly accelerate the diffusion and decay operators in the partial differential
equations used to represent biological transport in an agent-based biological
modeling system. In this paper, we utilize OpenACC to accelerate the diffusion
portion of PhysiCell, a cross-platform agent-based biosimulation framework. We
demonstrate an almost 40x speedup on the state-of-the-art NVIDIA A100 GPU
compared to a serial run on AMD's EPYC 7742. We also demonstrate 9x
speedup on the 64 core AMD EPYC 7742 multicore platform. By using
OpenACC for both the CPUs and the GPUs, we maintain a single source code
base, thus creating a portable yet performant solution. With the simulator's most
significant computational bottleneck significantly reduced, we can continue
cancer simulations over much longer times.
READ PAPER
Figure 5: Speedup normalized over serial

11. 11
RESOURCES
Paper: Portable Acceleration of Materials
Modelling Software: CASTEP, GPUs and
OpenACC
Matthew Smith, Arjen Tamerus, and Phil Hasnip
We present work to port the CASTEP first-principles materials
modelling program to accelerators using OpenACC. We
discuss the challenges and opportunities presented by GPGPU
architectures in particular, and the approach taken in the
CASTEP OpenACC port. Whilst the port is still under active
development, early performance results show that significant
speed-ups may be gained, particularly for materials simulations
using so-called ‘`non-local functionals,’' where speed-ups can
exceed a factor of ten.
READ PAPER
Figure 2: Performance of the initial and optimised
GPU ports, compared to a pure CPU calculation. The
benchmark was a ‘screened-exchange’ NLXC simulation of
bulk Fe2VAl. All simulations were performed
on the Ascent machine at ORNL, using 2 MPI tasks;
each task used either 21 CPU threads or 1 GPU.

12. 12
RESOURCES
Website: GPUHackathons.org
Technical Resources
VISIT SITE
Explore a wealth of resources for GPU-accelerated
computing across HPC, AI and Big Data.
Review a collection of videos, presentations, GitHub repos,
tutorials, libraries and more to help you advance your skills
and expand your knowledge.

13. 13
STAY IN THE KNOW:
JOIN THE OPENACC COMMUNITY
JOIN TODAY
The OpenACC specification is designed for, and
by, users meaning that the OpenACC organization
relies on our users’ active participation to shape
the specification and to educate the scientific
community on its use.
Take an active role in influencing the future of both
the OpenACC specification and the organization
itself by becoming a member of the community.

14. WWW.OPENACC.ORG
Learn more at