Large-paper embedding observation · V1

Embedding Studies

April 28, 2026 setup. Cross-machine embedding observation on the Sigma5C AI paper corpus — 326 papers, 104 PDFs, 92 extracted text records, ~8.5 million characters. Designed to test 14 embedding models under four chunking strategies (fixed-token, overlap, section-aware, TeX-aware) against seven retrieval tasks. A 48-thread Xeon CPU (157 GB RAM) provides the CPU baseline; GPU workstation with GTX 1070 provides the GPU worker. Vectors are stored on disk under content-addressed manifests — Postgres stores only provenance, scores, and artifact pointers.
papers
326
PDFs
104
characters
~8.5M
Xeon CPU embedding models
22
GPU workstation embedding models
55

How a paper becomes chunks

Fixed-token

Naive baseline

Constant-size sliding window (256 / 512 / 1024 tokens). No structural awareness. Reference baseline.

Overlap

Sliding window + overlap

Fixed token windows with 25-50% overlap between adjacent chunks. Reduces boundary loss at the cost of duplication.

Section-aware

Respect document structure

Split at section boundaries (abstract, introduction, methods, results, discussion). Chunks correspond to semantic units.

TeX-aware

Handle source TeX

Parse TeX commands; preserve equations as atomic chunks; strip rendering directives. The most demanding strategy.

What each model is tested on

  1. Known-title retrieval — given a paper title, return the paper
  2. Abstract-to-paper — given an abstract paragraph, return the source paper
  3. Method query — given a method description, return papers using that method
  4. Figure/table caption retrieval — given a caption, return the source paper
  5. Cross-paper related-work — given a paper, return related papers
  6. Code/dataset link recovery — given a paper, return its referenced code or dataset
  7. Cloud-model query generation — generate retrieval queries from raw text

Vectors on disk, metadata in Postgres

Explicit policy. Full embedding vectors live on disk as content-addressed manifests (SHA-256 of the chunk text plus the embedding-model name as the key). Postgres stores only the lightweight provenance and scoring layer — which chunk, which model, what retrieval task, what score, where on disk to find the vector. This keeps the database fast and small while preserving full reproducibility.

Models

Families

Companies

Related observations

AI-generated & AI-scored. Every observation on this site is produced and judged by AI, and AI makes mistakes. Treat each result as a recorded observation under a declared protocol, as of its date. Method and marker legend