Methodology

How the edition was made: methods, the model card, the evidence cut and its age, the acceptance record and the glossary.

13 min read0 figures13 tables17 notesNR-XTECH-HPC-GLOBAL-2026-BASELINE

Contents

A.1Methods

The global baseline uses published values and four simple derivations. Each is shown in full so that any reader can reproduce it.

Table A.1Methods
No.	Derivation	Calculation	Result
(1)	Combined power of the five largest systems, June 2026	42,220 + 29,685 + 24,607 + 38,698 + 15,794 kW	151,004 kW, about 151 MW
(2)	Growth of combined list performance in six months	18.73 ÷ 14.99	about 1.25 times
(3)	Share of listed systems that use accelerators	276 ÷ 500	55.2%
(4)	Ratio of El Capitan HPL-MxP to Linpack	16.7 ÷ 1.809	about 9.2 times

Table A.2Coupling strength scale (matrix and model card)
Strength	Definition
STRONG	a disruption in the source system has historically changed the target system’s service or output within one season, in more than one region
MODERATE	an effect is documented but buffered or slower
WEAK	an effect is plausible but not documented at global scale

Table A.3Status grammar
Label	Rule
Reported	value as issued by its source, with year
Inferred	reasoned from cited evidence; never a measurement
Estimated	Nexus analytical value with stated method
Scenario	conditional on stated assumptions
Expert input	structured editorial judgement awaiting evidence

A.2Model card, HPC System Model v0

Model ID: MDL-XT07-HPC · v0.1
Purpose: represent HPC and advanced computing as infrastructure coupled to electricity, cooling, chips, public funding, workforce and security policy
Family: graph-based system of systems
Inputs: the cited sources of this edition; no proprietary data
Method: expert-specified coupling strengths (STRONG · MODERATE · WEAK) from assessments and analogue events
Validation: none yet, first validation against federation evidence in 2027
Uncertainty: qualitative; strengths are hypotheses, not measurements
Domain of validity: global scale; not for asset-, site- or country-level use
Reproducibility: strength table and sources published in this edition

20couplings

typed in v0

0strong

documented within one season

0moderate

documented, buffered

20weak

plausible, undocumented

A.3The baseline evidence cut

Every Nexus edition is published from a frozen evidence cut. The global baseline cut is documentary: it pins the exact edition of every source cited. Federation cuts begin with the first national Foundry cuts in 2027.

Cut ID: DC-XTECH-HPC-GLOBAL-2026-B0
Type: baseline documentary cut
Resolution policy: pinned · as of 30 September 2026
Sources pinned: 43 cited sources, each at the edition and access date in the references
Model runs: none at baseline, analytical values are stated with their method
Digest: computed at freeze and recorded in the publication record
Supersedes: nothing, first cut of the series
Superseded by: the 2027 HPC annual cut

Lineage

01
source edition
02
pinned citation
03
finding
04
page
05
publication record

Table A.4From the baseline cut to the federation cut
Element	Baseline 2026	2027 global annual
Sources	cited global publications, pinned by edition	national, regional and sector cuts through one graph
Analysis	stated methods and editorial estimates	typed analysis specifications
Models	HPC System Model v0 specification	model runs with receipts
Findings	twelve baseline findings	findings re-bound to federation evidence
Review	five passes scheduled	five passes on the exact digest

A.4Evidence age and coverage

A 2026 global edition rests on evidence observed in many different years. This page shows each time base, so that no single year label hides older evidence.

Table A.5Evidence age and coverage
Indicator	Observed	Released	Cadence	Next release
Top-system results	2026	June 2026	periodic	November 2026 list
Efficiency results	2026	June 2026	periodic	November 2026 list
US data centre energy	2023	December 2024	one-off	next national report
Export rule timeline	2026	April and May 2026	per event	further guidance
EuroHPC budget	2021 to 2027	page read 2026-11-03	continuous	regulation changes
Footprint papers	2021 to 2024	preprints and papers	one-off	new studies
MPI and OpenMP	2024 to 2026	June 2025 · July 2026	periodic	OpenMP 6.1
FugakuNEXT plan	2025	August 2025	one-off	detailed design

Table A.6Coverage by system at baseline
System	Coverage	Thinnest dimension
Systems	GOOD	unlisted systems
Efficiency	PARTIAL	facility-level figures
Energy	PARTIAL	common basis for facilities
Governance	PARTIAL	text of rules and guidance
Investment	PARTIAL	public funding outside the US and EU
Supply	THIN	accelerator and memory supply
Skills	THIN	workforce numbers
Water	THIN	cooling-water use

Table A.7Designed empty states: what is not bound, what would fill it and why
Field	Source that would fill it	Blocker
Cooling-water use of large computing facilities	operators, national laboratories, regulators under the EU scheme	not retrieved; no primary figure read
Facility energy and demand on a common basis for HPC and for commercial AI workloads	national statistics, operators, IEA	one national figure read through a DOE news item¹²; the IEA report was not opened²⁸
IEA Energy and AI figures from the report itself	IEA Energy and AI²⁸	the report pages returned an access error; figures come from search summaries
Lawrence Berkeley report text, including water use	LBNL 2024 United States Data Center Energy Usage Report²⁹	report pages returned an access error; share and range come from a DOE news item¹²
Power draw and cost of JUPITER from primary pages	EuroHPC, Jülich Supercomputing Centre	power and budget are not stated on the page read⁹; list value only¹
LineShine architecture and independent description	operator and peer-reviewed or institutional papers	list pages only; secondary reports not opened³⁰
Specifications and schedules of DOE Solstice, Equinox, Lux and Discovery	Argonne and Oak Ridge system pages³¹	Argonne page returned an access error; Oak Ridge pages name the systems without specifications⁸²⁷; search summaries disagree on dates
El Capitan system description from the laboratory	Lawrence Livermore National Laboratory³²	page returned an access error; list values only¹
Text of the 2023 US advanced computing rule	Federal Register³³	page redirected; not opened
EU delegated regulations on data centre reporting and rating from the primary text	EUR-Lex³⁴³⁵	EUR-Lex returned no content; details come from law firm summaries
Supply of accelerators, high-bandwidth memory and fabrication capacity for HPC	industry and trade statistics	not retrieved; no figure used
HPC workforce size and skills gaps	national statistics, OECD, industry surveys	not retrieved; capability rung stays LISTED
Survey data on data centre efficiency and density	Uptime Institute global survey⁴²	page returned an access error; no figure used
Public funding totals for HPC outside the US and EU	national strategies and ministries	not consolidated; UK plan gives no budget figure²³
Results of the November 2026 TOP500 list	TOP500 news and lists⁶	not yet published at page read; the news page shows June 2026 as latest
Capability rungs beyond list monitoring, planning and funding	agencies, operators, laboratories	not reviewed

A.5Evidence cards, two anchor sources

Published by the TOP500 project at ISC 2026 on 23 June 2026, 67th edition. Periodic. Role: binds INF-001 and the dashboard power figures. Coverage: systems that submit results.

EVD-XT07-001

TOP500 list of June 2026¹

Published by the TOP500 project on the same date. Periodic. Role: binds ENE-004. Coverage: listed systems that report power.

EVD-XT07-002

Green500 list of June 2026³

Table A.8Quality dimensions at baseline
Dimension	EVD-XT07-001	EVD-XT07-002
Completeness	submitted systems only	listed systems that report power
Timeliness	twice a year	twice a year
Revision	new list replaces old	new list replaces old
Method transparency	benchmark method published	power method stated by the project
External validation	results reported by submitters	results reported by submitters

Evidence cards to follow in 2027

TOP500⁶: the November 2026 list
IEA²⁸: report text on data centre demand
EUR-Lex³⁴³⁵: delegated regulations from the primary text
Argonne and Oak Ridge³¹⁸: system specifications

A.6Publication acceptance record

Editorial self-check at evidence close. Every applicable item carries a disposition; the remaining items are review, approval and deposit.

Table A.9Publication acceptance record
Group	Area	Items	Pass	N/A	Pending
D1	Identity and scope	8	8	0	0
D2	Source and data	12	9	1	2
D3	Analysis and models	12	3	8	1
D4	Findings and claims	9	8	0	1
D5	Figures, tables, maps	10	6	2	2
D6	Editorial and citations	10	8	0	2
D7	Review and approval	13	0	0	13
D8	Artefact and design	12	7	0	5
D9	Registry and release	9	0	0	9

Publication gate

Conditions met: 14 of 23 at evidence close
Blocking problems: none recorded
Open conditions: reviews, approval of the exact digest, deposit, registry pointer

Not applicable at baseline

Model runs: first runs in Q1 2027
Maps: plates in Q2 2027
Waivers: none

A.7Status words

Table A.10The status every value carries
Status	What it means
Observed	Measured directly and published by the source.
Reported	Published statistics of an official or institutional source.
Declared	Stated by the body concerned; not independently measured.
Estimated	A Nexus estimate from cited evidence, with its method in Annex A.
Modelled	Produced by a stated model from cited inputs.
Inferred	Reasoned from cited evidence; not measured.
Forecast	A projection by the cited source.
Simulated	A simulation result under stated assumptions.
Scenario	A conditional statement under stated assumptions; never a prediction.
Expert input	Expert judgement, recorded with its basis.
Candidate	Proposed for a later edition; not yet evidence.
Evidence-quality levels (EQL 1 to 5) grade the source behind a value; they are not a score of the subject.

A.8How the edition is made, released and corrected

Every edition is built from a sealed evidence cut, reviewed under three keys, signed and deposited before any site shows it as published; corrections go to Nexus Standards as change proposals and feed the next cut.

Step	What happens	Source
01 Evidence arrives from the pillars	Foundry seals observations and indicator series, Universe hands over after-action and scenario findings, and contributions are screened at every gateway, including this site’s.
02 The cut is sealed	On the cut date the evidence is pinned under one identifier, so anyone can rebuild the edition from exactly what it was built on.
03 The edition is assembled	The edition is drafted from its template and content pack. Agents may draft; they never publish and never decide.
04 The keys turn	At the publisher of record the truth key comes first: every value is checked against its source or stated method before the meaning and capital keys turn. No edition moves on until every key has been turned by a named steward.
05 The gate opens	A named approver releases one exact digest of the edition; any change after this point is a new version, never a silent edit.
06 Signed and deposited	The PDF, the web edition and the data bundle are signed together with a manifest and an RO-Crate description, and deposited on Zenodo with a concept and a version DOI.
07 Published on its desk’s site	Only then does the edition show as published on its desk’s Reports site, and the Collection lists it as a part.
08 Corrections go to Standards	Method and correction findings go to Nexus Standards as change proposals; citations, corrections and new contributions feed the next evidence cut.

A teaching model of the process, not a forecast and not a record of any run; dates and counts on this page come from the programme record. Sources: Reports governance at GCRI Canada (2026); Zenodo, repository of record for Reports deposits (2026).

Lifecycle, one state at a time: Draft, Computed, Evidence bound, Reviewed, Approved for release, Published, Corrected, Superseded. This edition is a draft.

A.9Glossary and abbreviations

Table A.11Series terms
Term	Meaning
Baseline Edition	the inaugural annual edition that fixes the reference state for the series
WEFH+B	water, energy, food, health and biodiversity, the national nexus core
Coupling	a typed dependency through which one system transmits to another
Protection gap	the share of losses not covered by insurance
Capability ladder	LISTED → EXISTS → ADEQUATE → TESTED → DEMONSTRATED
EQL	evidence-quality level, 1–5
Evidence cut	a frozen resolution of exact sources and versions
NNC · NLC · NWG	National Nexus Consortium · National Leadership Council · National Working Groups

Table A.12Abbreviations used in this edition
Abbreviation	Expansion
BIS	Bureau of Industry and Security
CPU	central processing unit
DOE	US Department of Energy
ECP	Exascale Computing Project
EF	exaflops
GPU	graphics processing unit
HBM	high-bandwidth memory
HPC	high-performance computing
HPCG	High Performance Conjugate Gradients benchmark
HPL-MxP	mixed-precision High Performance Linpack benchmark
PUE	power usage effectiveness
TWh	terawatt-hours

A.10Technical annex

Table A.13Technical annex
Item	Annex	Contents	Status
A.1	Indicator definitions	the global indicator set, with units and sources	IN THIS EDITION
A.2	Coupling strengths	the twenty-cell matrix and its rationale	IN THIS EDITION
A.3	Scenario specification	SCN-XT07-PWR-01 assumptions and signposts	IN THIS EDITION
A.4	Capability placements	rung evidence for fifteen functions	IN THIS EDITION
A.5	Model diagnostics	first runs and validation	2027
A.6	Sensitivity analyses	influence of coupling strengths	2027
A.7	Cluster notes	cards for the major exascale and data centre clusters	2027
A.8	Review statements	pass-by-pass review record	AT RELEASE

A.1 · indicator definition: Linpack result (Rmax)

Construct: sustained speed of a dense linear solve at the largest size the system can run
Unit: floating-point operations per second, shown here in exaflops
Method: the Linpack benchmark run by the submitter and reported to the list
Source: TOP500 list, June 2026¹
Uncertainty: reported by submitters; not independently repeated here
Known limits: one benchmark; dense algebra only; not a measure of useful scientific output

Notes

Numbers are the edition’s reference numbers, so a note reads the same in every chapter. The full list, with every source and its licence, is in Annex C. Annex C, references

12US Department of Energy (ed.), DOE releases new report evaluating increase in electricity demand from data centres (news item, 20 December 2024; 176 TWh in 2023, 4.4% of US electricity; 6.7% to 12% projected for 2028). US Department of Energy, Washington. Observation year 2023. Accessed 2026-11-03.back
28UNVERIFIED, not opened: IEA (ed.), Energy and AI (2025; about 415 TWh for data centres in 2024, about 945 TWh in 2030), taken from press and search-result summaries; the IEA pages returned an access error. International Energy Agency, Paris. Observation year 2024. Accessed 2026-11-03.back
29UNVERIFIED, not opened: Shehabi, A. et al., 2024 United States Data Center Energy Usage Report, Lawrence Berkeley National Laboratory, December 2024; figures taken from a DOE news item [12]; the report pages returned an access error. Observation year 2023. Accessed 2026-11-03.back
9EuroHPC Joint Undertaking (ed.), JUPITER launching Europe’s exascale era (news item, 5 September 2025; about 24,000 GH200 superchips; warm-water cooling; funding shares; power and budget not stated). EuroHPC JU, Luxembourg. Observation year 2025. Accessed 2026-11-03.back
1TOP500 (ed.), TOP500 list, June 2026, 67th edition (list page; top systems, Rmax, Rpeak, cores and power). TOP500 project, Hamburg. Observation year 2026. Accessed 2026-11-03.back
30UNVERIFIED, not opened: HPCwire (ed.), Surprise: Chinese LineShine takes number 1 on TOP500 (23 June 2026), and press coverage that China had stopped submitting to the list in 2023, taken from search-result summaries; the HPCwire page returned an access error. Observation year 2026. Accessed 2026-11-03.back
31UNVERIFIED, not opened: Argonne National Laboratory (ed.), Genesis Mission systems (Solstice and Equinox; reported plans of 100,000 and 10,000 NVIDIA Blackwell GPUs, vendor-stated AI performance figures), taken from search-result summaries that disagree on dates; the page returned an access error. Observation year 2026. Accessed 2026-11-03.back
8Oak Ridge Leadership Computing Facility (ed.), compute systems (index page; Lux and Discovery labelled as introduced; no specifications). Oak Ridge National Laboratory, Oak Ridge. Observation year 2026. Accessed 2026-11-03.back
27Oak Ridge National Laboratory (ed.), The Genesis Mission (page; Lux and Discovery listed with one-line descriptions only). Oak Ridge National Laboratory, Oak Ridge. Observation year 2026. Accessed 2026-11-03.back
32UNVERIFIED, not opened: Lawrence Livermore National Laboratory (ed.), El Capitan verified as world’s fastest supercomputer (news item, November 2024), not retrieved; list values only. Observation year 2024. Accessed 2026-11-03.back
33UNVERIFIED, not opened: US Department of Commerce Bureau of Industry and Security, Implementation of Additional Export Controls: Certain Advanced Computing Items; Supercomputer and Semiconductor End Use (Federal Register, 25 October 2023), not retrieved; the page redirected. Observation year 2023. Accessed 2026-11-03.back
34UNVERIFIED, not opened: European Commission, Commission Delegated Regulation (EU) 2024/1364 of 14 March 2024 on the first phase of the establishment of a common Union rating scheme for data centres (500 kW threshold, annual reporting by 15 May), taken from law firm summaries; EUR-Lex returned no content. Observation year 2024. Accessed 2026-11-03.back
35UNVERIFIED, not opened: POST-CLOSE, context only: Noerr (ed.), note of October 2026 on the proposal of 21 September 2026 for a delegated regulation on an EU data centre rating scheme with grades A to G from 2027, taken from search-result summaries; preparatory working draft (2026). Observation year 2026. Accessed 2026-11-03.back
42UNVERIFIED, not opened: Uptime Institute (ed.), Global Data Center Survey 2025, not retrieved; the page returned an access error; no figure used. Uptime Institute, New York. Observation year 2025. Accessed 2026-11-03.back
23UK Government (ed.), AI Opportunities Action Plan (page; expand the AI Research Resource by at least 20 times by 2030; non-AI HPC and exascale flagged as unresolved; no budget figure). Department for Science, Innovation and Technology, London. Observation year 2025. Accessed 2026-11-03.back
6POST-CLOSE, context only: TOP500 (ed.), TOP500 news index (headlines and dates of the lists of November 2024, June 2025, November 2025 and June 2026; no November 2026 list at page read). TOP500 project, Hamburg. Observation year 2026. Accessed 2026-11-03.back
3TOP500 (ed.), Green500 list, June 2026 (list page; top five by gigaflops per watt). TOP500 project, Hamburg. Observation year 2026. Accessed 2026-11-03.back

Cite this annex

Valadbaygi, S. (Ed.). (2026). Annex A: Methodology. In Exponential Technology Report 2026: HPC and Advanced Computing (Baseline Edition 2026, Report No. NR-XTECH-HPC-GLOBAL-2026-BASELINE) [Draft under review]. The Global Centre for Risk and Innovation (GCRI).

Every citation form of the whole report, BibTeX and RIS included, is on the edition home. Cite this report

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