δ-mem: Efficient Online Memory for Large Language Models (arxiv.org)
198 points by 44za12 18 hours ago
djoldman 11 hours ago
I would love for the standard to be to ALWAYS report the required amount of memory to load and run a model in bytes of RAM alongside any other metrics. I'd love to see time to first token, token throughput, token latency as well but I'd settle for memory size as described above.
Essentially, many people want to know what the minimum amount of memory is to run a particular model.
Parameter count obscures important details: what are the sizes of the parameters? A parameter isn't rigorously defined. This also gets folks into trouble because a 4B param model with FP16 params is very different from a 4B param model with INT4 params. The former obviously should be a LOT better than the second.
This would also help with MOE models: if memory is my constraint, it doesn't matter if the (much larger RAM required) MOE version is faster or has better evals.
I'm waiting for someone in anger to ship the 1 parameter model where the parameter according to pytorch is a single parameter of size 4GB.
usernametaken29 17 hours ago
> δ-mem compresses past information into a fixed-size state matrix updated by delta-rule learning
This doesn’t solve the capacity problem of memory. You can cram more into one context window, but then again you need to associate them with input queries. That’s very hard because slight variations in input create hugely different activations. So really, it doesn’t improve caching. This paper might do a thing or two approximating the compression limit for context windows, but there’s a fundamental limit on how much information can go into it. What you really need is contextual search, as in, different events and objects with the same abstractions and semantic lead to same response, so you can cache effectively… on this front the paper does little to improve “memory” in a meaningful way
jsemrau 15 hours ago
I am currently working on deep context query which uses dynamically generated regex to pull only the relevant context blocks. By using lightweight RegEx pattern matching to detect semantic intent and filter structured context sections accordingly, you avoid the attention degradation that comes from stuffing semantically redundant information into the window
https://jdsemrau.substack.com/p/tokenmaxxing-and-optimizing-...
structuredPizza 14 hours ago
The more real world use cases we see, the more we see the use of a well thought out regex as a bridge from probabilistic to deterministic.
ogogmad 3 hours ago
This is one of the most interesting comments I've read on this website.
pbronez 4 hours ago
Interesting approach.
> Prioritize recall over precision.
Have you tried stemming your regex? That would help you catch messages where a different form of your word appeared. For example instead of “story” you look for “stor” which catches “stories” as well.
Then you might think, could we do an even better job by figuring out the general semantic intent of the query and history? Let’s project them into a semantic vector space! That’s an embedding.
Then you want to query that, which means you need a vector database. So now we can take the query, embed it, query the vector DB with that embedding and retrieve the N closest history documents. You can use that to augment the generation of the response to your prompt.
This is RAG.
Anyway, interesting to see different degrees of sophistication here. Certainly a handful of naive regex are very snappy.
There’s probably a hybrid approach where you use sophisticated NLP and embedding techniques to robustly define topics, then train a regex to approximate that well.
jsemrau 4 hours ago
vdelpuerto 10 hours ago
I wrote something about it trying to look other way around the context or memory data in models. The gravitational pull of information stills very hard to manage. Ive been using "functional scars" about 30 days now and getting good results in repetitive mistakes across sesions. https://github.com/VDP89/fscars
in-silico 7 hours ago
While there is a limit to the amount of information you can fit in a fixed-size state, the theoretical ceiling is pretty high.
A Hebbian associative matrix (one of the simplest and weakest memory constructions) can store about 0.7 bits of information per parameter. If you have a state with 300M parameters (the size of a Llama 3 8B KV cache at 10K context length), and a context with 2.1 bits of entropy per token (a reasonable estimate), then the state can encode 100M tokens worth of information.
Real models obviously aren't powerful enough to operate at the limit, but you can see why this is a promising research direction.
usernametaken29 6 hours ago
While 100 million tokens sounds a lot, think about it for a bit, and you’ll see why it is basically nothing. Try to cram a human lifetime of sounds, smells, video and more sensory data into 100 million tokens. Heck, try to process the video plot of a single series into that window. It just won’t work, it won’t scale, and is laughable compared to contextual memory. I’m not saying that to belittle the authors of the paper but the reality is that this has very little to do with transient long term memory.
in-silico 5 hours ago
ltbarcly3 6 hours ago
jandrese 14 hours ago
So instead of a FIFO approach to memory management it instead continually degrades the existing data the more you put in? Details start getting lost or mangled more and more over time?
trollbridge 11 hours ago
That’s basically what happens.
As you hit the limits and try to compact the context, etc., things get more erratic.
kordlessagain 15 hours ago
Like Ferricula: https://deepbluedynamics.com/ferricula (site/docs still in progress).
jmward01 2 hours ago
The future is fixed size state with a massive token history that the model can look back at like reading a journal. A reframing of the model this way opens a new kind of agent, one with essentially unlimited context, that packs perfectly on a GPU, can be stored/retrieved fairly effortlessly and can essentially be run forever. Fixed size means theta 1 tokens. A model that can look around also means essentially unlimited memory can be bolted on with the model learning to look around memory like it is looking around at the journal of past tokens. Guided windows of attn can do most of this, some other tricks can do the rest.
maxignol 7 hours ago
Is there some kind of memory enabling, for instance, an agent to remember guidelines on a repo without having to feed at the beginning of each session 4 markdown files and spending the corresponding tokens each time ?
airstrike 7 hours ago
No, it's all just prompts.
You can try to summarize memories tersely and point the agent to longer markdown files, but who knows if it will read it at the right time and only then.
3form 17 hours ago
Interesting points:
- fixed size of the memory seems like a good idea to overcome the current limitations
- skimming through the thing, I can't find any mention of the cost?
- I would need more time to read it in-depth to see if this is legitimate and not just fancy form of overfitting or training on testing data
in-silico 8 hours ago
They basically just added DeltaNet hypernetworks to existing LLMs.
Nothing super novel or groundbreaking, but a moderately interesting read.
raverbashing 16 hours ago
Interesting that the headline is showing Δ-Mem while the paper uses δ-mem
Is it a lowercase to uppercase conversion going on here?
sillysaurusx 16 hours ago
Correct!
DeathArrow 17 hours ago
I see lots of techniques proposed to give LLM the capacity to recall things, I even saw a lot of memory plugins for AI coding agents, I tried some myself.
What I want to see is something that was tested and proved in practice to be genuinely useful, especially for coding agents.
cjonas 12 hours ago
Coding agents don't really need memory. Agent skills, rules, git history, documentation is all far more efficient, transparent and easier to manage. These memory frameworks only really makes sense if you are building a consumer facing agent with managed context and limited capabilities.
wren6991 12 hours ago
There's an antipattern where everyone wants to invent new interfaces to connect things LLMs when CLI tools are already right there, transparent, and usable by humans as well as LLMs. I think it's partly the origins in web chat applications.
Beads kind of does "LLM memory over CLI", or there is https://github.com/wedow/ticket which is a minimal and sane implementation of the same idea.
stephantul 17 hours ago
How would you conceptualize recall in this case? Is searching through the current version of your code and possibly git history not enough?
rush86999 17 hours ago
You would think git history should be the first thing an agent would look at, as they make so many mistakes before they get to the correct answer. They don't.
I haven't measured, but documenting bug fixes and architecture seems to help, along with TDD patterns, including integration tests.
I would probably add it to Claude.md to look for all of the above when tackling a new bug.
visarga 15 hours ago
brookst 15 hours ago
DeathArrow 9 hours ago
>Is searching through the current version of your code and possibly git history not enough?
While you can document everything and use git history, I think that having short entries in a kind of memory to remember past decisions, how issues were solved would be much more token efficient than reading lots of documentation and looking at git history and past code.
ktallett 17 hours ago
The obvious energy saving step would be to utilise previous searches by others. Many of the tasks people do are rather similar, it is such an energy waste to start again each time.
(Obviously ignoring the huge energy saver, which is to observe if you even need to bother doing the task at all.)
405126121 17 hours ago
I had this thought and created https://pushrealm.com which is essentially a sort of Stackoverflow written by agents.
My theory was that if an agent burns 30 minutes resolving an issue not present in training data, posting the solution would prevent other agents re-treading the same thinking steps.
TheTaytay 11 hours ago
Fascinating! Do you have a way to detect/flag malicious stuff by any chance? (Seems like a good vector for prompt injection, but maybe no more than any other internet site?)
ktallett 16 hours ago
I see why, but I don't feel this is the solution. Being able to search thru the endless LLM responses is not viable. However having useful memories, similar to human brain is more important. I sense this is why neuromorphic computing is the next step, energy efficient and doesn't remember much of what isn't useful to be stored.
visarga 15 hours ago
spockz 17 hours ago
So you mean caching? :-)
duskdozer 17 hours ago
A lot of what I see people using LLMs for would be more cheaply and reliably done by [scripts]. A search engine style suggestion thing like "Have you tried `sed`?" would be beneficial imo
tyre 15 hours ago
In my experience, Claude is more than happy to go to Unix tools rather than write its own. Sometimes it will write a lil python script to solve something, but more often than not it’ll pipe together Unix utilities.
This has the benefit of it knowing all of the arcane flags, especially for formatting output.
duskdozer 12 hours ago
semiquaver 14 hours ago
Hmm, this is a case where HN’s title mangling changed the meaning of the title. Lower case delta (δ) is used intentionally. I don’t think HN should automatically modify the casing of non-ascii chars.
setopt 14 hours ago
Even for ASCII chars, nomenclature in math and physics is usually case-sensitive.
cwillu 12 hours ago
Email [email protected] and they'll fix it.
airstrike 12 hours ago
The submitter has a grace period of a few minutes to edit the title after submitting, so there's no need to change what HN does
realitysballs 10 hours ago
True, but wouldn’t it be better long term if website automation didn’t create unintended new meanings to Titles? title’s matter
airstrike 7 hours ago
throw1234567891 7 hours ago
cubefox 15 hours ago
Papers being voted high on Hacker News are usually uncorrelated with their actual importance. It's basically a lottery. There are regularly more interesting papers going semi viral on Twitter.
MeteorMarc 15 hours ago
On huggingface it was #3 paper of the day, which is neutral towards your hypothesis.
cubefox 9 hours ago
Considering that there is a paper with this many points perhaps once a week here (probably less), #3 of the day is pretty unremarkable.
kingkawn 15 hours ago
What about broad unsupportable generalizations on hackernews, how do those rank?