TANGO/CoNGA@SC25: Dancing Toward More Sustainable Cyberinfrastructure

Original Article by Elizabeth Leake | January 16, 2026

In early 2025, John Gustafson asked if STEM-Trek would consider collaborating with the Conference on Next-Generation Arithmetic (CoNGA) to join our annual pre-conference workshop ahead of the Supercomputing Conference, SC25. I enthusiastically said, “yes!” Since 2019, I’ve closely followed activity in Dr. Gustafson’s realm. It’s exciting that next-generation arithmetic is found to process artificial intelligence/Machine Learning (AI/ML) and other data-intensive computational workloads with greater accuracy and fewer bits which addresses both energy and storage challenges.

Dr. Gustafson is chiefly known among mathematicians as the father of Gustafson’s law. He currently serves as Visiting Scholar at Arizona State University and Chief Scientist at Vq Research, Inc. Prior roles include Chief Graphics Product Architect and Senior Fellow at AMD, Solutions Architect at Intel Labs-SC, CEO of Massively Parallel Technologies, Inc. and CTO at ClearSpeed Technology. Historically, CoNGA was hosted by the Agency for Science, Technology and Research (A*STAR) in Singapore where Dr. Gustafson worked prior to returning to the U.S. in 2022. COVID prevented in-person assemblies for a few years, and CoNGA has been slow to gain traction with him this side of the pond.

Adhering to a dance theme, we established the “TANGO” moniker for this year’s workshop – a celebration of nonTraditional Architecture and Next-Gen Computational Orchestration. Also in collaboration with Texas A&M University, STEM-Trek hosted TANGO@SC25 at the America’s Center in St. Louis, Missouri. While a TANGO dance demonstration was performed by Horst Severini (U-Oklahoma) and Liwen Shih (U-Houston – Clear Lake), dancing shoes were not required to learn how Compute eXpress Link (CXL), RISC-V and Next-Gen Math are driving a revolution toward more efficient supercomputers.

While the math was new to most attendees, several CoNGA papers were presented that explained why it’s important, and how it’s being implemented. As research workflows become more data-intensive and complex, there is a need for greater acceleration (NVIDIA GPUs being the popular choice). Federated GPU-heavy systems are fully-subscribed, and the community demands more. The practice of adding more and more acceleration is costly. However, innovation that employs next-generation arithmetic (Posits, Takums, etc.), CXL and RISC-V technologies is tackling both power and storage challenges for AI/ML workflows, while paving the way for quantum computing which will invariably rely on all of the above plus alternate standards. TANGO acquainted participants with basic steps; all enjoyed meeting others from around the world who work in similar roles. Having coalesced over two days, the TANGO cohort felt more comfortable jumping into the deep end of the SC25 conference that drew 16,500 attendees and 650 exhibitors.

TANGO convened November 14-15 ahead of SC25, November 16–22. Our traditional “jetlag day” was Friday, November 14. This year it was open to all who wanted to join, and travel awards included an additional two days’ coverage. Even so, it’s difficult for some to take ten days away from their day job. Therefore, Saturday’s gathering was larger – 50 attended from eight countries – our largest cohort to date. Two missed the group photo, and two others who aren’t in the photo had joined from Calligo Tech (India). Calligo produced the first Posits-based accelerator; Posits was developed by Dr. Gustafson with decades of effort.

Each participant brought unique skills, experience and insights to the cohort. Interesting discussions were had during breaks and meals. It’s always gratifying when they remark that our workshop was the highlight of their SC experience, which several have done in their blogs. While Leon Pollock (Dell Solutions Consultant/AI) had a business case to attend ART@SC24, he returned on his own this time because he found it to be so beneficial last year. He was front-and-center at every session!

Pollock wrote: “Thank you for welcoming me to your program again this year. I bought Dr. Gustafson’s book; last night I set up a Jupyter Notebook so that I can gain practical knowledge of Takums in the coming year. I created a learning plan with accountability check-ins and milestones that will deliver the foundation of my portfolio development. I’m truly inspired and grateful to STEM-Trek for hosting this event!”

Leon made arrangements with Sauce on the Side, the restaurant that hosted Saturday’s group dinner, to serve decorated cakes that he brought to celebrate 21st and 21st (again; ahem) birthdays. He is always welcome in our community!

Jetlag Day was held Friday, November 14; we were guests of T-Kartor, Esri, T-Rex, and others. The venue was a short walk from the America’s Center; the Post Building once housed the Pulitzer-prize winning newspaper, and is now home to a variety of startups, including geographic information system (GIS) research labs that exist within the orbit of the National Geospatial-Intelligence Agency (NGA) based in East St. Louis. While NGA work is classified, those who contribute were happy to share highlights of their work with the TANGO/CoNGA cohort. They are interested in expanding their GIS ecosystem and are always recruiting.

The Post Building houses remnants of the old press operation and production line including a slide once used to move papers from the press down one level to be loaded onto delivery trucks. Today, it serves as a human slide. Everyone, including Himeshi De Silva (Singapore) featured in this photograph, had huge smiles on their faces when they tried it out!

After the GIS presentations at the Post Building, 20 from the cohort visited Top Notch Axe-Throwing and enjoyed a pizza party. Vasilka Chergarova (AmLight), Senzo Mpungose (U-Witwatersrand), and Sean Feeney (Texas A&M University) demonstrated their skills (from left, below; photos by Liwen Shih, U-Houston).

On Saturday, we gathered at the America’s Center. CoNGA kicked off with a talk by Dr. Gustafson, and a keynote by Jeffrey Sarnoff (IEEE). Sarnoff talked about his work with IEEE P3109 Standard for Machine Learning Arithmetic. With more than 40 years of experience at the forefront of computer science, software engineering and digital innovation, Sarnoff is well qualified to lead this effort. He pioneered early 3D graphics in the 1980’s and currently leads IEEE high-impact initiatives in numerical computing and software standards. Early in his career, he taught one of the first college-level courses that bridged art and computing at the Rhode Island School of Design. More recently, he has been recognized for exceptional contributions to IEEE technical standards, open-source communities and industry-leading organizations.

Sarnoff combines deep technical expertise in floating-point arithmetic, computer graphics and high-performance computing with proven leadership in cross-functional teams and industry consortia. As an open-source evangelist, he has authored numerous Julia programming language packages, including: DoubleFloats.jl (extended precision arithmetic), NamedTupleTools.jl, Saferintegers.jl, RollingFunctions.jl, ArbNumerics.jl and more. Sarnoff holds an MBA from Cornell University, attended Stanford University as an undergraduate and graduated from Bennington College with majors in Computer Science and Psychology. Photo by Bryan Johnston (CHPC South Africa).

A call for papers had been released by CoNGA in May. Several authors were on hand to present their papers, from as far as Singapore. Participant blogs are available on the STEM-Trek website. A two-hour hands-on Julia training session was led by Jeffrey Sarnoff, with Texas A&M HPRC trainers Wesley Brashear and TAMU Faculty Member Jian Tao. From the Julia website: Julia is a high-level, high-performance programming language designed for technical computing, especially in areas like scientific computing, machine learning and data analysis. It aims to combine the ease of use of Python with the speed of languages like C and Fortran. Julia is dynamically typed and supports interactive use, making it suitable for both prototyping and deploying complex applications. 

While all were welcome to apply for the TANGO@SC25 workshop, this series has historically served participants from NSF EPSCoR regions in the U.S. and Southern African Development Community (SADC) member states that participate in the African High Performance Computing (HPC) Ecosystems project led by the South African Centre for HPC. All who are involved with or curious about next-generation arithmetic, CXL and RISC-V innovation were welcome to apply this year.

On Sunday, all engaged with the full SC conference. Most wrote about the technical sessions they attended in their blogs. On Wednesday evening many attended Dell’s customer appreciation event at FanDuel Sports Live at Ballpark Village. A caricature artist drew portraits; this is my favorite photo from the week. These students’ smiles were infectious. That’s Honggao Liu (far left), Executive Director of the High Performance Research Computing Team at Texas A&M University – my TAMU boss. This photo was taken by my HPRC colleague, Steve Tran (TAMU Systems Engineer).

By November 21 (my third 21st – ahem – birthday) most had departed. With government shutdown-related issues that week, many flights were canceled. Seven who remained joined me at the Marriott Courtyard Downtown for another dinner from Sauce on the Side, located just around the corner. All found St. Louis merchants to be very accommodating and of great value! It will be a favored vacation destination for me in the future.

The CoNGA workshop drew several from Germany this year, including Laslo Hunhold, Senior AI Accelerator Engineer at Openchip & Software Technologies (Barcelona). He said, “Ultimately, human connections are the true value of attending a conference in person, and I am deeply grateful for the opportunity to attend TANGO/CoNGA and SC25. Much like the Gateway Arch in St. Louis, such gatherings serve as a portal to the unknown: the uncharted territory of computing and scientific progress. What makes the journey worthwhile is knowing that, on this frontier, there are capable and passionate people alongside you, ready to explore, experiment and push the limits together.”

History of the STEM-Trek pre-conference workshop

TANGO/CoNGA@SC25 was the seventh in a series of SC co-located workshops that STEM-Trek has hosted since 2015. The previous six were supported by the U.S. National Science Foundation (NSF; supplements to existing grants, or individual awards), and donations to STEM-Trek. The first, in collaboration with Executive Director Dan Stanzione at the Texas Advanced Computing Center (TACC), was for systems administrators and research facilitators. The second: “HPC On Common Ground@SC16,” in collaboration with the University of Oklahoma and Oklahoma State University, focused on food security science. URISC@SC17 provided cybersecurity training and was co-facilitated by Indiana University and the NSF Trusted-CI program. Funding lapsed in 2018–19, and activities were less communal at SC20–21 due to COVID (ScienceSlams were held online). In 2022, we held the first in-person workshop in five years titled, EarthSci@SC22. NRG@SC23 was a convening to discuss energy-related challenges in resource-constrained environments. ART@SC24, in coordination with Texas A&M University, home of the novel NSF-funded ACES (Accelerating Computing for Emerging Sciences) composable testbed, had an artificial intelligence theme and drew 43 participants. ART@SC24 explored the benefits and pitfalls of AI, and complexities associated with AI/ML workflows.

We hope everyone will join us in “Sweet Home Chicago” for SC26 – HPC Unites! We haven’t chosen a theme for the STEM-Trek pre-conference workshop yet, but if you have suggestions, we’d love to hear them. For more information about STEM-Trek, please visit our website.

Thank you sponsors, collaborators and friends!

I wish to express my appreciation for Kurt Keville (Somerville Dynamics) and Bryan Johnston (South African Centre for HPC) for their help throughout the year with planning.

The SC25 General Chair Lori Diachin (Principal Deputy Associate Director, Computing Directorate at Lawrence Livermore National Laboratory) graciously donated 18 full tech program registrations (including workshops and tutorials), our meeting space and AV support. These were provided to applicants who most needed them. We were awarded a grant from the US NSF (23-1 Program for Education and Workforce Development) and carried forward NSF funds from the same program that weren’t used last year. Additionally, Micron, AMD and other STEM-Trek donations supported international participant costs, our affinity garment (black jacket with red trim and TANGO graphic), international delegate and student pre-paid visas (in lieu of per diem), and group meals. While Dell proper couldn’t financially contribute this year, their reps connected us with the AMD entity that could. We are grateful for all who helped!

About the author: Elizabeth Leake is an HPCwire contributor and founder of STEM-Trek, a global nonprofit that supports underrepresented STEM scholars with travel and professional development. She is also a project manager of advanced cyberinfrastructure at Texas A&M University.