Preface  i

Summary  ii

Figures  vii

Tables  vii

Abbreviations  viii

Acknowledgements  x

1. Introduction  x

2. Methodology  3

2.1. Literature review  3

2.2. Expert consultations  3

2.3. Quantitative estimation  4

2.4. Definition of 'Europe'  4

2.5. Limitations  5

3. What is distributed training and why is it useful?  7

3.1. What is distributed training, and what is it not?  7

3.2. Why is distributed training useful?  8

3.3. Recent research advances  10

4. Distributed training as a potential solution to infrastructure bottlenecks  14

4.1. Power  14

4.2. Compute  19

4.3. Politics  23

5. Cross-cutting risks and limitations of distributed training  27

5.1. Operational complexity and coordination costs  27

5.2. Talent requirements  28

5.3. Unproven at frontier scale and issues in future-proofing  28

5.4. Additional challenges  29

6. Recommendations – making Europe ready for distributed training  30

6.1. An illustrative scenario  30

6.2. Policy recommendations  32

References  35

Annex A. Converting between H100 equivalents and power capacity  44

A.1. Source 1: RAND (Pilz, Mahmood & Heim 2025)  44

A.2. Source 2: Epoch AI (Sevilla et al. 2024)  44

A.3. Averaged estimate  44

A.4. Caveats  45