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!

Is Data Science the Fourth Pillar of the Scientific Method?

April 18, 2019

Nvidia CEO Jensen Huang revived a decade-old debate last month when he said that modern data science (AI plus HPC) has become the fourth pillar of the scientific method. While some disagree with the notion that statistic Read more…

By Alex Woodie

At ASF 2019: The Virtuous Circle of Big Data, AI and HPC

April 18, 2019

We've entered a new phase in IT -- in the world, really -- where the combination of big data, artificial intelligence, and high performance computing is pushing the bounds of what's possible in business and science, in w Read more…

By Alex Woodie with Doug Black and Tiffany Trader

Google Open Sources TensorFlow Version of MorphNet DL Tool

April 18, 2019

Designing optimum deep neural networks remains a non-trivial exercise. “Given the large search space of possible architectures, designing a network from scratch for your specific application can be prohibitively expens Read more…

By John Russell

HPE Extreme Performance Solutions

HPE and Intel® Omni-Path Architecture: How to Power a Cloud

Learn how HPE and Intel® Omni-Path Architecture provide critical infrastructure for leading Nordic HPC provider’s HPCFLOW cloud service.

powercloud_blog.jpgFor decades, HPE has been at the forefront of high-performance computing, and we’ve powered some of the fastest and most robust supercomputers in the world. Read more…

IBM Accelerated Insights

Bridging HPC and Cloud Native Development with Kubernetes

The HPC community has historically developed its own specialized software stack including schedulers, filesystems, developer tools, container technologies tuned for performance and large-scale on-premises deployments. Read more…

Interview with 2019 Person to Watch Michela Taufer

April 18, 2019

Today, as part of our ongoing HPCwire People to Watch focus series, we are highlighting our interview with 2019 Person to Watch Michela Taufer. Michela -- the General Chair of SC19 -- is an ACM Distinguished Scientist. Read more…

By HPCwire Editorial Team

At ASF 2019: The Virtuous Circle of Big Data, AI and HPC

April 18, 2019

We've entered a new phase in IT -- in the world, really -- where the combination of big data, artificial intelligence, and high performance computing is pushing Read more…

By Alex Woodie with Doug Black and Tiffany Trader

Interview with 2019 Person to Watch Michela Taufer

April 18, 2019

Today, as part of our ongoing HPCwire People to Watch focus series, we are highlighting our interview with 2019 Person to Watch Michela Taufer. Michela -- the Read more…

By HPCwire Editorial Team

Intel Gold U-Series SKUs Reveal Single Socket Intentions

April 18, 2019

Intel plans to jump into the single socket market with a portion of its just announced Cascade Lake microprocessor line according to one media report. This isn Read more…

By John Russell

BSC Researchers Shrink Floating Point Formats to Accelerate Deep Neural Network Training

April 15, 2019

Sometimes calculating solutions as precisely as a computer can wastes more CPU resources than is necessary. A case in point is with deep learning. In early stag Read more…

By Ken Strandberg

Intel Extends FPGA Ecosystem with 10nm Agilex

April 11, 2019

The insatiable appetite for higher throughput and lower latency – particularly where edge analytics and AI, network functions, or for a range of datacenter ac Read more…

By Doug Black

Nvidia Doubles Down on Medical AI

April 9, 2019

Nvidia is collaborating with medical groups to push GPU-powered AI tools into clinical settings, including radiology and drug discovery. The GPU leader said Monday it will collaborate with the American College of Radiology (ACR) to provide clinicians with its Clara AI tool kit. The partnership would allow radiologists to leverage AI techniques for diagnostic imaging using their own clinical data. Read more…

By George Leopold

Digging into MLPerf Benchmark Suite to Inform AI Infrastructure Decisions

April 9, 2019

With machine learning and deep learning storming into the datacenter, the new challenge is optimizing infrastructure choices to support diverse ML and DL workfl Read more…

By John Russell

AI and Enterprise Datacenters Boost HPC Server Revenues Past Expectations – Hyperion

April 9, 2019

Building on the big year of 2017 and spurred in part by the convergence of AI and HPC, global revenue for high performance servers jumped 15.6 percent last year Read more…

By Doug Black

The Case Against ‘The Case Against Quantum Computing’

January 9, 2019

It’s not easy to be a physicist. Richard Feynman (basically the Jimi Hendrix of physicists) once said: “The first principle is that you must not fool yourse Read more…

By Ben Criger

Why Nvidia Bought Mellanox: ‘Future Datacenters Will Be…Like High Performance Computers’

March 14, 2019

“Future datacenters of all kinds will be built like high performance computers,” said Nvidia CEO Jensen Huang during a phone briefing on Monday after Nvidia revealed scooping up the high performance networking company Mellanox for $6.9 billion. Read more…

By Tiffany Trader

ClusterVision in Bankruptcy, Fate Uncertain

February 13, 2019

ClusterVision, European HPC specialists that have built and installed over 20 Top500-ranked systems in their nearly 17-year history, appear to be in the midst o Read more…

By Tiffany Trader

Intel Reportedly in $6B Bid for Mellanox

January 30, 2019

The latest rumors and reports around an acquisition of Mellanox focus on Intel, which has reportedly offered a $6 billion bid for the high performance interconn Read more…

By Doug Black

It’s Official: Aurora on Track to Be First US Exascale Computer in 2021

March 18, 2019

The U.S. Department of Energy along with Intel and Cray confirmed today that an Intel/Cray supercomputer, "Aurora," capable of sustained performance of one exaf Read more…

By Tiffany Trader

Looking for Light Reading? NSF-backed ‘Comic Books’ Tackle Quantum Computing

January 28, 2019

Still baffled by quantum computing? How about turning to comic books (graphic novels for the well-read among you) for some clarity and a little humor on QC. The Read more…

By John Russell

IBM Quantum Update: Q System One Launch, New Collaborators, and QC Center Plans

January 10, 2019

IBM made three significant quantum computing announcements at CES this week. One was introduction of IBM Q System One; it’s really the integration of IBM’s Read more…

By John Russell

Deep500: ETH Researchers Introduce New Deep Learning Benchmark for HPC

February 5, 2019

ETH researchers have developed a new deep learning benchmarking environment – Deep500 – they say is “the first distributed and reproducible benchmarking s Read more…

By John Russell

Leading Solution Providers

SC 18 Virtual Booth Video Tour

Advania @ SC18 AMD @ SC18
ASRock Rack @ SC18
DDN Storage @ SC18
HPE @ SC18
IBM @ SC18
Lenovo @ SC18 Mellanox Technologies @ SC18
One Stop Systems @ SC18
Oracle @ SC18 Panasas @ SC18
Supermicro @ SC18 SUSE @ SC18 TYAN @ SC18
Verne Global @ SC18

IBM Bets $2B Seeking 1000X AI Hardware Performance Boost

February 7, 2019

For now, AI systems are mostly machine learning-based and “narrow” – powerful as they are by today's standards, they're limited to performing a few, narro Read more…

By Doug Black

The Deep500 – Researchers Tackle an HPC Benchmark for Deep Learning

January 7, 2019

How do you know if an HPC system, particularly a larger-scale system, is well-suited for deep learning workloads? Today, that’s not an easy question to answer Read more…

By John Russell

Arm Unveils Neoverse N1 Platform with up to 128-Cores

February 20, 2019

Following on its Neoverse roadmap announcement last October, Arm today revealed its next-gen Neoverse microarchitecture with compute and throughput-optimized si Read more…

By Tiffany Trader

France to Deploy AI-Focused Supercomputer: Jean Zay

January 22, 2019

HPE announced today that it won the contract to build a supercomputer that will drive France’s AI and HPC efforts. The computer will be part of GENCI, the Fre Read more…

By Tiffany Trader

Intel Launches Cascade Lake Xeons with Up to 56 Cores

April 2, 2019

At Intel's Data-Centric Innovation Day in San Francisco (April 2), the company unveiled its second-generation Xeon Scalable (Cascade Lake) family and debuted it Read more…

By Tiffany Trader

Microsoft to Buy Mellanox?

December 20, 2018

Networking equipment powerhouse Mellanox could be an acquisition target by Microsoft, according to a published report in an Israeli financial publication. Microsoft has reportedly gone so far as to engage Goldman Sachs to handle negotiations with Mellanox. Read more…

By Doug Black

HPC Reflections and (Mostly Hopeful) Predictions

December 19, 2018

So much ‘spaghetti’ gets tossed on walls by the technology community (vendors and researchers) to see what sticks that it is often difficult to peer through Read more…

By John Russell

Oil and Gas Supercloud Clears Out Remaining Knights Landing Inventory: All 38,000 Wafers

March 13, 2019

The McCloud HPC service being built by Australia’s DownUnder GeoSolutions (DUG) outside Houston is set to become the largest oil and gas cloud in the world th Read more…

By Tiffany Trader

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