This document provides a summary of highlights from the 2020 GPU Technology Conference (GTC) related to OpenACC, including: - OpenACC is a programming model for parallel computing on CPUs and GPUs using compiler directives. - GTC 2020 content included sessions on using OpenACC across various disciplines like weather modeling, seismic imaging, and computational fluid dynamics. - Presentations, tutorials, posters, and "Connect with Experts" sessions provided information on OpenACC optimizations, multi-GPU programming, and applications in various domains.

1. Highlights from GTC Digital: April 2020
OPENACC HIGHLIGHTS

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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.org Consortium

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GPU TECHNOLOGY CONFERENCE:
A FLAGSHIP CONFERENCE FOR DEVELOPERS
GTC Digital is the great training, research,
insights, and direct access to the brilliant
minds of NVIDIA’s GPU Technology
Conference, now online.
Mark your calendar to view the GTC 2020
Keynote by NVIDIA CEO Jensen Huang
starting Thursday, May 14. Starting May 19,
join us for new live webinars, demos, and
recorded talks discussing the very latest in AI,
HPC, data science, graphics, and more.

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NVIDIA’S GPU TECHNOLOGY CONFERENCE
A COMPLETELY DIGITAL EXPERIENCE
READ BLOG
Amidst the growing concern over the
coronavirus, NVIDIA decided to focus on the
safety of employees, partners and community
as the top priority and take its flagship GPU
Technology Conference (GTC) completely
digital.
Additionally, NVIDIA decided to offer the
hundreds of hours of technical, relevant
content—live webinars, recorded talks,
technical demos, and Connect with Experts—
for FREE!

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OPENACC AT GTC20
ACROSS DISCIPLINES AND PLATFORMS
VIEW CONTENT
From weather and climate to seismic imaging to
aeronautics, OpenACC sessions featured at GTC20
are helping to facilitate discussions, educate
attendees and encourage networking and
collaboration.
Sessions cover a broad range of topics, the “Meet the
Experts” session enabled one-on-one deep dives into
using OpenACC to solve specific challenges, posters
highlight how OpenACC is being applied to current
science applications, and the on-demand tutorial
delivers hands-on skills building.

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“CONNECT WITH EXPERTS” SESSION
ON-DEMAND RECORDING
LISTEN TO SESSION
OpenACC is a programming model designed
to help scientists and developers to start with
GPUs faster and be more efficient by
maintaining a single code source for multiple
platforms.
OpenACC experts discuss how to start
accelerating your code on GPUs, continue
optimizing your GPU code, start teaching
OpenACC, host or participate in a hackathon,
and more.

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WATCH SESSION
Richard Loft, Director of Technology
Development, Computational and
Information Systems Laboratory at the U.S.
National Center for Atmospheric Research
(NCAR), presents “Toward an Exascale
Earth System Model with Machine Learning
Components: An Update.”
This session provides an update on
achieved performance portability for Model
for Prediction Across Scales-Atmosphere
(MPAS-A) and discusses additional NCAR
efforts.
WORKING TO IMPROVE WEATHER AND
CLIMATE MODELING

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VIEW SESSION
Join Total SA as they discuss how they ported
modern seismic applications like Reverse Time
Migration, Full Wave Inversion, and One-Way
Migration to the GPU-accelerated Pangea III
supercomputer. This session will explain decisive
code transformations to take full advantage of the
computing power of GPUs, present different CUDA
optimization techniques to achieve an asynchronous
implementation entirely overlapping communications
with the propagation kernels, compare OpenACC
and CUDA programming models, and outline a new
hybrid GPU-CPU data compression algorithm that
vastly outperforms the CPU version.
FULLY EXPLOITING A GPU SUPERCOMPUTER
FOR SEISMIC IMAGING

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WATCH SESSION
David Gutzwiller, software engineer and head of
HPC at Numeca, presents “Toward Industrial
LES/DNS in Aeronautics: Leveraging OpenACC for
Massively Parallel CPU+GPU Simulations.”
This session describes the development of FineFR,
a high-order CFD solver supporting heterogeneous
CPU+GPU architectures, emphasizes the highly
tuned OpenACC implementation, and presents
benchmark data and demonstration computations
from the OLCF Summit Supercomputer.
TOWARD INDUSTRIAL LES/DNS
COMPUTATIONAL FLUID DYNAMICS

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LISTEN TO SESSION
WalmartLabs presents “GPU-Accelerated Tabu
Search and Large Neighborhood Search to Solve
Vehicle Routing Problem with Time Windows” which
introduces a Tabu Search algorithm designed to
exploit the parallelism in neighborhood search and its
OpenACC-based implementation that applies deep-
copy and manages complex data types.
The session also covers an Adaptive Large
Neighborhood Search algorithm in which various
combinations of destroy-and-repair heuristics are
adaptively applied during the optimization process for
the exploration of a substantially wider neighborhood
of the solution space.
SOLVING LARGE-SCALE VEHICLE
ROUTING PROBLEMS

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WATCH TUTORIAL
Learn how to program multi-GPU
systems or GPU clusters using the
message-passing This tutorial starts with
a quick introduction to MPI and how it
can be combined with OpenACC or
CUDA, then covers advanced topics like
CUDA-aware MPI and how to overlap
communication with computation to hide
communication times.
TUTORIAL: MULTI-GPU PROGRAMMING
WITH MESSAGE-PASSING INTERFACE

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VIEW POSTER
Presented by Ron Caplan from Predictive
Sciences, this poster illustrates how to
optimize a stencil operation within the
production solar physics research code
Magnetohydrodynamics Around a Sphere.
The author explores numerous OpenACC
directive options and compares their
performance over several problem types
and sizes.
POSTER: OPTIMIZING STENCIL OPERATIONS
IN OPENACC

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VIEW POSTER
This poster, presented by University of
Tokyo, shows how OpenACC is useful for
GPU porting of a soil liquefaction analysis
solver with FP21-FP32-FP64 mixed-
precision computing. The approach
achieved a 10.7-fold speedup over the
CPU-based solver on a system where the
ratio of peak FP64 FLOPS was CPU:GPU
= 1:10.2 and took only three weeks for a
beginning GPU programmer to port the
solver to GPU.
POSTER: LOW-COST OPENACC PORTING OF
EARTHQUAKE APPLICATION

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VIEW POSTER
Interested in characterizing spatial structure
inherent in 3D scalar fields from simulated or
imaged data? This poster presents an
accelerated solution for Minkowski functionals—
widely applied in cosmology, material science,
engineering, microbial ecology, and health
care—using both OpenACC and CUDA on
commodity GPUs. The poster presents methods
to minimize the memory footprint, and hence
reduce data-transfer costs, and highlights the
additional methods to further enhance and fine-
tune the performance of the CUDA solution.
POSTER: RUNTIME ANALYSIS OF
SPATIAL STRUCTURE

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VIEW POSTER
The Weather Research and Forecasting
(WRF) model is the most widely used
regional weather forecasting model and a top
5 HPC application worldwide. Presented by
Samuel Elliott of TempoQuest Inc., this poster
discusses the GPU implementation of the
model as well as performance benchmarks
demonstrating the model’s practical
performance benefits. TQI has also
developed a cloud-based solution for running
end-to-end AceCAST GPU-WRF workflows
on AWS.
POSTER: ACECAST GPU-ENABLED WEATHER
RESEARCH AND FORECASTING MODEL

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VIEW POSTER
The pipelined accelerator (PACC) helps
lower the hurdle for implementing out-of-
core stencil computation, such as large
seismic simulations. In this poster,
Jincheng Shen from Osaka University
introduces temporal blocking techniques to
reuse on-chip data, and propose a data-
mapping scheme to eliminate data
movement on the host side. The data-
mapping scheme accelerates the program
by 2.5x compared to previous work and by
35x compared to an OpenMP-based
program.
POSTER: ACCELERATING LARGE SEISMIC
SIMULATION CODE WITH PACC FRAMEWORK

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