OpenACC Shines in Global Climate/Weather Codes

By John Russell

November 14, 2017

OpenACC, the directive-based parallel programming model used mostly for porting codes to GPUs for use on heterogeneous systems, came to SC17 touting impressive speedups of climate codes as well as its latest release, version 2.6, which adds deep copy functionality but otherwise minor enhancements. The progress reported demonstrates OpenACC’s steady and impactful penetration of the HPC landscape.

Three of the top five HPC applications[i] (ANSYS Fluent, Gaussian, and VASP) now support and use OpenACC, and on the order of 85 applications have been “accelerated” at hackathons since 2014. The work on climate codes – conducted over a few years – includes recent successful efforts by a 2017 Gordon Bell finalist to speed up the widely used Community Atmosphere Model (CAM) from The National Center for Atmospheric Research (NCAR) on China’s Sunway TaihuLight Supercomputer.

“OpenACC allowed us to scale the CAM-SE to over 1.8 million Sunway cores with a simulation speed of over 3 simulated years per day,” said Haohuan Fu, deputy director of the National Supercomputing Center in Wuxi NAD in OpenACC’s SC17 announcement. “Without OpenACC, the team would have spent years coding for the complexity of the components in the TaihuLight Supercomputer.”

It seems increasingly clear that OpenACC is finding its place in the HPC toolbox. The spotlighting of work done with climate and weather forecasting codes is one example.

Code speedup in climate research is important because of the time scales tackled. Stan Posey, program manager, earth system modeling solution development at NVIDIA, told HPCwire, “Climate research might model decades of climate behavior and so you want to achieve as many simulated years per day as you can. I believe at the Department of Energy they have gotten to about 1.5 simulated years per day which is about the best I have seen until this announcement.”

He noted the work on Sunway “is not related to GPUs; it’s just strictly the Chinese indigenous system but they used OpenACC because they don’t have the kinds of tools and compilers and so forth. It’s still such a new design.”

It’s worth pointing out that most climate models have two distinct parts, according to Posey, “One half to solve what’s called the dynamics and one half to solve the physics. The dynamics covers the transport or the CFD that’s required in these models. Then we have the physics which handles processes such as turbulence and so on.” The two tasks have somewhat different computational requirements.

“The [physics] have a higher opportunity for performance gains because they operate not necessarily embarrassingly parallel but they operate in individual vertical columns so you can process many of these at once, which is what GPUs really like. Meanwhile the dynamics part of the model is about 50 percent of the total profile and that’s nearly always going to be limited to the 2X-3X range improvement,” he said. The latter limits potential performance gains for the overall model. Speedups are achieved by attacking amenable portions of the code.

OpenACC has been proving its effectiveness in climate models. NCAR, for example, developed an atmospheric model called Model for Prediction Across Scales (MPAS). In collaboration with the University of Wyoming, and the Korea Institute of Science and Technology Information (KISTI), the team evaluated various platforms and programming models, and implemented the MPAS with OpenACC directives to take advantage of fine grain parallel processing on GPUs. Scientists at NCAR and University of Wyoming developed OpenACC code for the MPAS dynamical core and scientists at KISTI developed OpenACC code for the MPAS physics in a project that will implement the full MPAS model on GPUs.

“Our team has been investigating OpenACC as a pathway to higher performance, and with performance portability for the MPAS global atmospheric model,” said Rich Loft, director of technology development at the NCAR Computational Information and Systems Laboratory in the release. “Using this approach for the MPAS dynamical core, we have achieved speedups on a single P100 GPU equivalent to nearly 3 CPU nodes on our new Cheyenne supercomputer.”

Other climate and weather forecasting work cited by OpenACC included:

  • COSMO. Scientists at MeteoSwiss, ETH Zurich, and the Swiss National Supercomputing Center (CSCS) have developed the physics of the COSMO regional atmospheric model in OpenACC to deploy on GPUs for use in operational numerical weather prediction, and climate research.
  • IFS. Collaboration with ECMWF in the ESCAPE Project has demonstrated speedups of more than an order of magnitude when optimizing existing GPU code for the spectral transform operations in the IFS Details were presented at the ESCAPE Workshop during Sep 2017.
  • NICAM. Computational scientists at RIKEN have achieved GPU factors speedup over CPU-only, for the NICAM-DC (dynamical core) project using OpenACC on more than 1000 GPU nodes of the TSUBAME 2.5 supercomputer at the Tokyo Institute of Technology.
  • The paper “Parallelization and Performance of the NIM Weather Model on CPU, GPU, and MIC Processors,” published in the Oct 2017 edition of BAMS, describes the OpenACC and GPU developments by scientists at the NOAA Earth System Research Laboratory to achieve performance portability with the same FORTRAN code compiled across various types of HPC platforms.

OpenACC also presented favorable benchmarks for speeding up ANSYS Fluent, Guassian, and VASP with significant speedups.

“On the right side of the slider are the CAAR codes (Center for Accelerated Application Readiness) for CORAL systems, and five of those also use OpenACC to use the accelerator but also to express parallelism potentially for the CPU side.” CARR is a collaborative effort of application development teams and staff from the OLCF Scientific Computing group, CAAR is focused on redesigning, porting, and optimizing application codes for Summit’s hybrid CPU–GPU architecture.

There wasn’t much change in membership. Michigan State University has completed the process and Juckeland said another organization would soon complete the process. He also emphasized OpenACC’s commitment supporting many platforms. Arm is still not supported. AMD was a late addition to the SC17 briefing slide.

[i] Top five HPC applications according to Intersect360 Research: 1 Gromacs, 2 ANSYS Fluent, 3 Gaussian, 4 VASP, and 5 NAMD

Subscribe to HPCwire's Weekly Update!

Be the most informed person in the room! Stay ahead of the tech trends with industy updates delivered to you every week!

LLNL Leverages Supercomputing to Identify COVID-19 Antibody Candidates

March 30, 2020

As COVID-19 sweeps the globe to devastating effect, supercomputers around the world are spinning up to fight back by working on diagnosis, epidemiology, treatment and vaccine development. Now, Lawrence Livermore National Read more…

By Staff report

Weather at Exascale: Load Balancing for Heterogeneous Systems

March 30, 2020

The first months of 2020 were dominated by weather and climate supercomputing news, with major announcements coming from the UK, the European Centre for Medium-Range Weather Forecasts and the U.S. National Oceanic and At Read more…

By Oliver Peckham

Q&A Part Two: ORNL’s Pooser on Progress in Quantum Communication

March 30, 2020

Quantum computing seems to get more than its fair share of attention compared to quantum communication. That’s despite the fact that quantum networking may be nearer to becoming a practical reality. In this second inst Read more…

By John Russell

SiFive Accelerates Chip Design with Cloud Tools

March 25, 2020

Chip designers are drawing on new cloud resources along with conventional electronic design automation (EDA) tools to accelerate IC templates from tape-out to custom silicon. Among the challengers to chip design leade Read more…

By George Leopold

What’s New in Computing vs. COVID-19: White House Initiative, Frontera, RIKEN & More

March 25, 2020

Supercomputing, big data and artificial intelligence are crucial tools in the fight against the coronavirus pandemic. Around the world, researchers, corporations and governments are urgently devoting their computing reso Read more…

By Oliver Peckham

AWS Solution Channel

Amazon FSx for Lustre Update: Persistent Storage for Long-Term, High-Performance Workloads

Last year I wrote about Amazon FSx for Lustre and told you how our customers can use it to create pebibyte-scale, highly parallel POSIX-compliant file systems that serve thousands of simultaneous clients driving millions of IOPS (Input/Output Operations per Second) with sub-millisecond latency. Read more…

DoE Expands on Role of COVID-19 Supercomputing Consortium

March 25, 2020

After announcing the launch of the COVID-19 High Performance Computing Consortium on Sunday, the Department of Energy yesterday provided more details on its scope and operation in a briefing led by Undersecretary of Ener Read more…

By John Russell

Weather at Exascale: Load Balancing for Heterogeneous Systems

March 30, 2020

The first months of 2020 were dominated by weather and climate supercomputing news, with major announcements coming from the UK, the European Centre for Medium- Read more…

By Oliver Peckham

Q&A Part Two: ORNL’s Pooser on Progress in Quantum Communication

March 30, 2020

Quantum computing seems to get more than its fair share of attention compared to quantum communication. That’s despite the fact that quantum networking may be Read more…

By John Russell

DoE Expands on Role of COVID-19 Supercomputing Consortium

March 25, 2020

After announcing the launch of the COVID-19 High Performance Computing Consortium on Sunday, the Department of Energy yesterday provided more details on its sco Read more…

By John Russell

[email protected] Rallies a Legion of Computers Against the Coronavirus

March 24, 2020

Last week, we highlighted [email protected], a massive, crowdsourced computer network that has turned its resources against the coronavirus pandemic sweeping the globe – but [email protected] isn’t the only game in town. The internet is buzzing with crowdsourced computing... Read more…

By Oliver Peckham

Conversation: ANL’s Rick Stevens on DoE’s AI for Science Project

March 23, 2020

With release of the Department of Energy’s AI for Science report in late February, the effort to build a national AI program, modeled loosely on the U.S. Exascale Initiative, enters a new phase. Project leaders have already had early discussions with Congress... Read more…

By John Russell

Servers Headed to Junkyard Find 2nd Life Fighting Cancer in Clusters

March 20, 2020

Ottawa-based charitable organization Cancer Computer is on a mission to stamp out cancer and other life-threatening diseases, including coronavirus, by putting Read more…

By Tiffany Trader

Kubernetes and HPC Applications in Hybrid Cloud Environments – Part II

March 19, 2020

With the rise of cloud services, CIOs are recognizing that applications, middleware, and infrastructure running in various compute environments need a common management and operating model. Maintaining different application and middleware stacks on-premises and in cloud environments, by possibly using different specialized infrastructure and application... Read more…

By Daniel Gruber,Burak Yenier and Wolfgang Gentzsch, UberCloud

Intel’s Neuromorphic Chip Scales Up (and It Smells)

March 18, 2020

Neuromorphic chips attempt to directly mimic the behavior of the human brain. Intel, which introduced its Loihi neuromorphic chip in 2017, has just announced that Loihi has been scaled up into a system that simulates over 100 million neurons. Furthermore, it announced that the chip smells. Read more…

By Oliver Peckham

[email protected] Turns Its Massive Crowdsourced Computer Network Against COVID-19

March 16, 2020

For gamers, fighting against a global crisis is usually pure fantasy – but now, it’s looking more like a reality. As supercomputers around the world spin up Read more…

By Oliver Peckham

Julia Programming’s Dramatic Rise in HPC and Elsewhere

January 14, 2020

Back in 2012 a paper by four computer scientists including Alan Edelman of MIT introduced Julia, A Fast Dynamic Language for Technical Computing. At the time, t Read more…

By John Russell

Global Supercomputing Is Mobilizing Against COVID-19

March 12, 2020

Tech has been taking some heavy losses from the coronavirus pandemic. Global supply chains have been disrupted, virtually every major tech conference taking place over the next few months has been canceled... Read more…

By Oliver Peckham

[email protected] Rallies a Legion of Computers Against the Coronavirus

March 24, 2020

Last week, we highlighted [email protected], a massive, crowdsourced computer network that has turned its resources against the coronavirus pandemic sweeping the globe – but [email protected] isn’t the only game in town. The internet is buzzing with crowdsourced computing... Read more…

By Oliver Peckham

Steve Scott Lays Out HPE-Cray Blended Product Roadmap

March 11, 2020

Last week, the day before the El Capitan processor disclosures were made at HPE's new headquarters in San Jose, Steve Scott (CTO for HPC & AI at HPE, and former Cray CTO) was on-hand at the Rice Oil & Gas HPC conference in Houston. He was there to discuss the HPE-Cray transition and blended roadmap, as well as his favorite topic, Cray's eighth-gen networking technology, Slingshot. Read more…

By Tiffany Trader

DoE Expands on Role of COVID-19 Supercomputing Consortium

March 25, 2020

After announcing the launch of the COVID-19 High Performance Computing Consortium on Sunday, the Department of Energy yesterday provided more details on its sco Read more…

By John Russell

Fujitsu A64FX Supercomputer to Be Deployed at Nagoya University This Summer

February 3, 2020

Japanese tech giant Fujitsu announced today that it will supply Nagoya University Information Technology Center with the first commercial supercomputer powered Read more…

By Tiffany Trader

Tech Conferences Are Being Canceled Due to Coronavirus

March 3, 2020

Several conferences scheduled to take place in the coming weeks, including Nvidia’s GPU Technology Conference (GTC) and the Strata Data + AI conference, have Read more…

By Alex Woodie

Leading Solution Providers

SC 2019 Virtual Booth Video Tour

AMD
AMD
ASROCK RACK
ASROCK RACK
AWS
AWS
CEJN
CJEN
CRAY
CRAY
DDN
DDN
DELL EMC
DELL EMC
IBM
IBM
MELLANOX
MELLANOX
ONE STOP SYSTEMS
ONE STOP SYSTEMS
PANASAS
PANASAS
SIX NINES IT
SIX NINES IT
VERNE GLOBAL
VERNE GLOBAL
WEKAIO
WEKAIO

Cray to Provide NOAA with Two AMD-Powered Supercomputers

February 24, 2020

The United States’ National Oceanic and Atmospheric Administration (NOAA) last week announced plans for a major refresh of its operational weather forecasting supercomputers, part of a 10-year, $505.2 million program, which will secure two HPE-Cray systems for NOAA’s National Weather Service to be fielded later this year and put into production in early 2022. Read more…

By Tiffany Trader

Exascale Watch: El Capitan Will Use AMD CPUs & GPUs to Reach 2 Exaflops

March 4, 2020

HPE and its collaborators reported today that El Capitan, the forthcoming exascale supercomputer to be sited at Lawrence Livermore National Laboratory and serve Read more…

By John Russell

Summit Supercomputer is Already Making its Mark on Science

September 20, 2018

Summit, now the fastest supercomputer in the world, is quickly making its mark in science – five of the six finalists just announced for the prestigious 2018 Read more…

By John Russell

IBM Unveils Latest Achievements in AI Hardware

December 13, 2019

“The increased capabilities of contemporary AI models provide unprecedented recognition accuracy, but often at the expense of larger computational and energet Read more…

By Oliver Peckham

IBM Debuts IC922 Power Server for AI Inferencing and Data Management

January 28, 2020

IBM today launched a Power9-based inference server – the IC922 – that features up to six Nvidia T4 GPUs, PCIe Gen 4 and OpenCAPI connectivity, and can accom Read more…

By John Russell

TACC Supercomputers Run Simulations Illuminating COVID-19, DNA Replication

March 19, 2020

As supercomputers around the world spin up to combat the coronavirus, the Texas Advanced Computing Center (TACC) is announcing results that may help to illumina Read more…

By Staff report

University of Stuttgart Inaugurates ‘Hawk’ Supercomputer

February 20, 2020

This week, the new “Hawk” supercomputer was inaugurated in a ceremony at the High-Performance Computing Center of the University of Stuttgart (HLRS). Offici Read more…

By Staff report

Summit Joins the Fight Against the Coronavirus

March 6, 2020

With the coronavirus sweeping the globe, tech conferences and supply chains are being hit hard – but now, tech is hitting back. Oak Ridge National Laboratory Read more…

By Staff report

  • arrow
  • Click Here for More Headlines
  • arrow
Do NOT follow this link or you will be banned from the site!
Share This