Conditional Memory via Scalable Lookup: A New Axis of Sparsity for Large Language Models
Xin Cheng et al.
arXiv:2601.07372
In short
Engram adds a lookup memory to transformers, a modern take on N-gram embeddings retrieved in constant time, as a second kind of sparsity alongside mixture-of-experts. At 27B parameters it beats an equal-compute MoE model, helping reasoning, code and long-context retrieval more than expected.
Why it matters
It proposes memory lookup as a new scaling axis for LLMs, separate from compute.
Read first
The 4 Field Guide ideas this paper leans on.
Starting from scratch? The full route 13 ideas · basics first
- Dataset ✓ understood
A collection of data examples used for training, validating, or testing machine learning models.
- Feature ✓ understood
A single measurable property of an example, such as a house's floor area or how many links an email contains, used as an input to a model.
- Machine Learning ✓ understood
Building systems that learn patterns from data instead of following hand-written rules, getting better at a task as they see more examples.
- Neural Network ✓ understood
A computational model inspired by biological neural networks, consisting of interconnected nodes (neurons) organized in layers that process information through weighted connections.
- Deep Learning ✓ understood
A subset of machine learning that uses neural networks with multiple layers (deep neural networks) to learn hierarchical representations of data.
- Representation Learning ✓ understood
Learning useful features or representations of data automatically, rather than hand-crafting them.
- Embedding · read first ✓ understood
A list of numbers (a vector) that represents a word, sentence, image or other item, learned so that similar items end up close together.
- Attention Mechanism ✓ understood
A technique that lets a neural network weigh every part of its input when producing each output, focusing on the parts most relevant at that step.
- Transformer · read first ✓ understood
A neural network architecture, introduced in 2017, built from stacked self-attention and feed-forward layers; the basis of nearly every modern large language model.
- Feedforward Network ✓ understood
A neural network where information flows in one direction from input to output without cycles.
- Mixture of Experts · read first ✓ understood
An architecture where multiple specialized sub-networks (experts) process inputs, with a gating network routing to relevant experts.
- Token ✓ understood
The basic unit of text that a language model processes, typically representing a word, subword, or character. Tokens are the fundamental building blocks for LLM input and output.
- N-gram · read first ✓ understood
A contiguous sequence of n items (words, characters) from text, used in language modeling and feature extraction.
In the frontier
- Rank
- #93 of 100
- Citations
- 63
- as of Aug 9, 2026
- Published
- Jan 2026
Topics: Model architecture , Efficiency and serving , Long context and attention
Selection: 1kpapers.com by Together AI, most-cited as of Aug 9, 2026