Switzerland · operational · mixed

Alps

Deep dive: Isambard-AI versus Alps: two GH200 routes

Researched with AI assistance, checked by scripts. These rows were researched by AI agents reading public operator, laboratory and vendor sources, appended by scripts and checked by automated validation; no subject-matter expert has reviewed them (how this site is made). A mechanical second-reader pass has since fetched every cited source: 1350 of 1540 systems have a readable citation that names them, and 64 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: 434.9 PFlop/s
Rpeak: 574.8 PFlop/s
Rmax ÷ Rpeak: 75.7%
Cores: 2,121,600
Power: 7.12 MW
Per watt: 61.0 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	- HPE Cray EX254n	Hewlett Packard Enterprise HPENYSE	-	Reported	cscs.ch nvidia.com
Accelerator	NVIDIA GH200 Grace Hopper Superchip Accelerators Arm CPU + CUDA GPU · TSMC 4N NVIDIA GH200 Superchip, 4 per node	NVIDIA NVDANASDAQ	10,752 reported	Reported	cscs.ch nvidia.com
CPU	NVIDIA Grace CPUs Armv9 (Neoverse V2) · 72C · 3.1 GHz · TSMC 4N NVIDIA Grace 72C (in GH200)	NVIDIA NVDANASDAQ	-	Reported	cscs.ch nvidia.com
Interconnect	HPE Slingshot-11 Interconnect Dragonfly · 200 Gb/s per port · Around 2 microseconds Slingshot-11	Hewlett Packard Enterprise HPENYSE	-	Reported	cscs.ch nvidia.com
Storage	HPE Cray ClusterStor E1000 Storage Lustre appliance, flash and disk tiers · 700 PB on Frontier (Orion) · About 10 TB/s peak Lustre on ClusterStor	Hewlett Packard Enterprise HPENYSE	-	Reported	cscs.ch nvidia.com
Cooling	Direct liquid cooling, warm water Cooling Direct-to-chip cold plates, facility water loop · Removes 90+ percent of node heat to liquid direct liquid cooling	Hewlett Packard Enterprise HPENYSE	-	Reported	cscs.ch nvidia.com
Operating system	HPE Cray Operating System Operating systems SUSE-derived Linux, container-based management · Proprietary layer over open-source Linux HPE Cray Operating System	Hewlett Packard Enterprise HPENYSE	-	Reported	cscs.ch nvidia.com

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	10,752 accelerators	2026-10	Operator stated	GH200 superchips (2,688 nodes x 4), per CSCS and the Swiss AI Apertus report. Excludes the A100, MI250X and MI300A partitions.	cscs.ch arxiv.org
PUE	1.2	2022-01	Operator stated	CSCS states PUE 'below 1.2' for its Lugano data centre (lake-water cooling, 14 MW first circuit). Facility-wide, from a 2022 article, so an upper bound.	cscs.ch

The read

The first large European system built on NVIDIA's Grace Hopper superchip, which means NVIDIA occupies the CPU role and the accelerator role simultaneously: the same structural pattern as El Capitan, arrived at from the opposite direction. Alps is also explicitly built as a multi-tenant research infrastructure rather than a single-program machine, which is why its workload class is mixed rather than hpc.

Timeline

2021 Announced source
2024-03 First operational source
2024-06 List debut at #6 (June 2024) 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

CSCS, Lugano

Location: Lugano, Switzerland
Cooling: Lake-water cooling (Lake Lugano)
Commissioned: 2012

cscs.ch

Change history

2026-10-04 Added AI datacenter metrics for alps
2026-09-22 Gained a Green500 rank pointer (#14 on the 2024-11 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
cscs.ch	names system, part and count	NVIDIA Grace, HPE Slingshot-11, HPE Cray Operating System, HPE Cray ClusterStor E1000 · counts: 10752
nvidia.com	blocked our fetch	-

Checked 2026-10-18 by pnpm verify. Re-run it and the table changes with the web.

Related news

2025-09-02 ETH Zurich and EPFL release Apertus, a fully open LLM trained on Alps · ETH Zurich
Apertus used more than 10 million GPU hours on Alps to train 8B and 70B parameter models with open weights, data and training code, a rare case in this dataset of a system's compute being fully accounted for by one named downstream model rather than a mix of undisclosed workloads.
2025-01-23 Piz Daint powered off after 13 years, cleared for Alps · CSCS
CSCS retired the Cray XC50/XC40 system that had anchored Swiss GPU computing since 2012, closing out the last pre Grace Hopper system in this dataset's Swiss lineage and completing the multi year handover to Alps that began with Alps' 2024 inauguration.

All news →