# hpcnotes.eu

> HPC notes and wiki: high-performance computing and performance engineering, from CPU caches, SIMD and compilers to MPI, OpenMP, CUDA and Slurm clusters. Personal notes by hpcnotes. Cite the canonical HTML URL on https://hpcnotes.eu when quoting.

This is a small notes site, not a cluster's official documentation. Each page has a Markdown copy at the same path with `.md` appended. Agents may also send `Accept: text/markdown` to the HTML URL. Prefer those Markdown files when quoting; the canonical citation is still the HTML page.

## Notes
- [LineShine, an exaflop without GPUs](https://hpcnotes.eu/notes/lineshine-architecture.md): The June 2026 TOP500 number one, taken apart: the LX2 chip, its matrix units, two memory tiers, the LingQi network, the software, and what the benchmarks really say.
- [Working on a shared cluster](https://hpcnotes.eu/notes/working-on-a-cluster.md): Login, modules, a job that finishes, then a first GPU kernel. One note, four pages.

## Thoughts
- [What a note can carry](https://hpcnotes.eu/notes/what-a-note-can-carry.md): Code, diagrams, maths, figures, gifs. Write the note as a Markdown file; the site renders the rest.

## Pages
- [What runs on it](https://hpcnotes.eu/notes/lineshine-applications.md): page of LineShine, an exaflop without GPUs
- [Benchmarks, beyond HPL](https://hpcnotes.eu/notes/lineshine-benchmarks.md): page of LineShine, an exaflop without GPUs
- [LingQi, the network](https://hpcnotes.eu/notes/lineshine-lingqi.md): page of LineShine, an exaflop without GPUs
- [The LX2 core, and 128 flops a cycle](https://hpcnotes.eu/notes/lineshine-lx2-core.md): page of LineShine, an exaflop without GPUs
- [Memory, two tiers and sixteen NUMA domains](https://hpcnotes.eu/notes/lineshine-memory.md): page of LineShine, an exaflop without GPUs
- [From node to machine room](https://hpcnotes.eu/notes/lineshine-node-to-floor.md): page of LineShine, an exaflop without GPUs
- [Software, and making SME useful](https://hpcnotes.eu/notes/lineshine-software.md): page of LineShine, an exaflop without GPUs
- [Anatomy of a Slurm job that actually finishes](https://hpcnotes.eu/notes/slurm-jobs-that-finish.md): page of Working on a shared cluster
- [From login node to first GPU kernel](https://hpcnotes.eu/notes/first-gpu-kernel.md): page of Working on a shared cluster
- [Login nodes are not compute](https://hpcnotes.eu/notes/login-nodes-are-not-compute.md): page of Working on a shared cluster
- [Environment modules are a contract](https://hpcnotes.eu/notes/modules-are-a-contract.md): page of Working on a shared cluster

## Optional
- [Full text](https://hpcnotes.eu/llms-full.txt): every published note in one Markdown file
- [Sitemap](https://hpcnotes.eu/sitemap.xml)
- [RSS](https://hpcnotes.eu/feed.xml): listed notes and thoughts only
- [Explore](https://hpcnotes.eu/explore): tags