MareNostrum 5 ACC

Also known as MN5

Operated by Barcelona Supercomputing Center at Barcelona Supercomputing Center .

Phase 1 seed dataset, compiled by hand. These rows were built from public operator, laboratory and vendor sources. A mechanical second-reader pass has since fetched every cited source: 1263 of 1345 systems have a readable citation that names them, and 56 are genuinely weakly sourced. Every claim carries its source and a confidence tier. Treat anything below verified as a lead, not a citation.

Measured performance

Rmax: 138.2 PFlop/s
Rpeak: 265.6 PFlop/s
Rmax ÷ Rpeak: 52.0%
Cores: -
Power: -
Per watt: - GF/W

Figures are as last publicly reported for the configuration described below, not a live measurement. Where a system was upgraded in place, the post-upgrade configuration is shown and the earlier one appears in the timeline.

What this machine is made of

One row per supplier relationship. “Supplier at build” is the company that shipped the part at the time; where that company has since been acquired, the parent it rolls up to today is shown beside it. That distinction is what makes ticker-level aggregation possible across a thirty-year dataset.

Role	Part	Supplier at build	Quantity	Confidence	Source
Integrator	- Eviden BullSequana XH3000	Eviden ATOEPA rolls up to Atos	-	Reported	bsc.es eurohpc-ju.europa.eu
Accelerator	NVIDIA H100 SXM5 Accelerators CUDA (Hopper GH100) · 16,896C · 1.98 GHz · TSMC 4N · 700 W NVIDIA H100	NVIDIA NVDANASDAQ	-	Reported	bsc.es eurohpc-ju.europa.eu
CPU	Intel Xeon Platinum 8460Y+ CPUs x86-64 · 40C · 2 GHz · Intel 7 · 300 W Xeon Platinum 8460Y 40C 2.3GHz	Intel INTCNASDAQ	-	Reported	bsc.es eurohpc-ju.europa.eu
Interconnect	NVIDIA InfiniBand NDR (Quantum-2) Interconnect Fat tree or dragonfly+ · 400 Gb/s per port · Under 0.6 microseconds Infiniband NDR200	NVIDIA NVDANASDAQ	-	Reported	bsc.es eurohpc-ju.europa.eu
Storage	IBM Spectrum Scale ESS (GPFS) Storage Parallel filesystem (GPFS), erasure-coded declustered RAID · 250 PB on Summit (Alpine) · About 2.5 TB/s Elastic Storage Server (ESS-3500) units	IBM IBMNYSE	-	Reported	bsc.es arxiv.org
Cooling	Direct liquid cooling, warm water Cooling Direct-to-chip cold plates, facility water loop · Removes 90+ percent of node heat to liquid BullSequana XH3000: direct liquid cooled platform	Eviden ATOEPA rolls up to Atos	-	Reported	bsc.es eurohpc-ju.europa.eu
Operating system	Red Hat Enterprise Linux Operating systems Linux distribution · Open source, commercial support subscription Red Hat Enterprise Linux	Red Hat IBMNYSE rolls up to IBM	-	Reported	bsc.es eurohpc-ju.europa.eu

AI datacenter metrics

Figures beyond an accelerator count, each with who stated it. What can and cannot be compared across AI datacenters.

Metric	Value	As of	Basis	Note	Source
Accelerators	4,480 accelerators	2026-10	Operator stated	Accelerated partition: 1,120 nodes x 4 Hopper GPUs (H100 64 GB).	bsc.es
Facility power	20 MW	2026-10	Operator stated	EuroHPC page: BSC datacentre has total power capacity of 20 MW (cooling 17 MW). Site capacity for all MareNostrum 5 partitions.	eurohpc-ju.europa.eu
Model FLOPs utilisation	20.3 percent	2026-01	Third-party estimate	Median MFU in an external group's Qwen3-1.7B continued pretraining (phase 3, 400 H100 GPUs, 7.35M tok/s). Small model; not a flagship-scale run.	arxiv.org
PUE	1.08	2026-10	Operator stated	EuroHPC page: BSC datacentre PUE below 1.08. Stated upper bound, whole MareNostrum 5 facility.	eurohpc-ju.europa.eu

The read

The accelerated partition of MareNostrum 5, a EuroHPC system hosted by Barcelona. Eviden integration with Intel hosts and NVIDIA H100s - a three-vendor node in a programme explicitly intended to build European capability, which is precisely the tension the domestic-substitution index is designed to measure.

Timeline

2022 Announced source
2023-11 List debut at #8 (November 2023) source
2023-12 First operational source

Public list appearances

Pointers only: rank and edition, linking to the canonical entry. We do not reproduce list tables. See sourcing policy.

Site & facility

Barcelona Supercomputing Center

Location: Barcelona, Spain
Cooling: Direct liquid cooling
Commissioned: 2005

bsc.es

Change history

2026-10-04 Added AI datacenter metrics for marenostrum-5-acc
2026-09-22 Gained a Green500 rank pointer (#6 on the 2023-11 list)

Source check

We fetched this system's own citations and recorded whether each page actually mentions it. This is a corroboration signal, not a fact check, and it is published so you can see how well the sourcing holds up rather than take it on trust.

Cited source	Result	Found on the page
eurohpc-ju.europa.eu	names system and part	NVIDIA H100 SXM5, Direct liquid cooling, warm water, NVIDIA InfiniBand NDR (Quantum-2), IBM Spectrum Scale ESS (GPFS)
bsc.es	names system and part	Direct liquid cooling, warm water, Intel Xeon Platinum 8460Y+

Checked 2026-10-13 by pnpm verify. Re-run it and the table changes with the web.