alt Hacker NewsShow HN: Getting GLM 5.2 running on my slow computer
A few days ago I found myself trying out GLM 5.2 and was really positively impressed. The capabilities and security I was getting from this LLM are similar to those I've gotten from models like Claude or GPT, and this really surprised me.
But then I thought, "I wonder how it would work on a normal computer like mine," and above all, "I wonder if it would work without going into OOM on a computer like mine." So I started working with the help of agents to test this possibility.
I started converting the model to int4, understanding MTP usage, and if possible implementing DSA for long context. How it responds in int4 and whether the quality is maintained or not. Until I got to the point, on my computer with 32GB of RAM, I was able to communicate with GLM 5.2 with times that, of course, aren't high in cold start, but even then, we're talking about 0.1 tok/s, but that wasn't important to me. The important thing was the journey to reach this goal. I just wanted it to work at all costs, even slowly.
So I created Colibrì, which was born from a very simple idea, to be honest, but tested in every way, where a 744B Mixture-of-Experts model activates only ~40B parameters per token—and only ~11 GB of those change from token to token (the routed experts). So:
The dense part (attention, shared experts, embeddings—~17B params) stays resident in RAM at int4 (~9.9 GB); The 21,504 routed experts (75 MoE layers × 256 experts + the MTP head, ~19 MB each at int4) live on disk (~370 GB) and are streamed on demand, with a per-layer LRU cache, an optional pinned hot-store, and the OS page cache as a free L2.
The engine is a single C file (c/glm.c, ~1,300 lines) plus small headers. No BLAS, no Python at runtime, no GPU.No GPU or serious hardware because I don't have that hardware so I can't test it on hardware that is more powerful than my computer.Colibrì is a one-person project, written and tested entirely on a 12-core laptop with 25 GB of RAM — the numbers above are the ceiling of what I can measure at home.
Any feedback is welcome! (and if anyone wanted to participate in the project I would be delighted)
Comments
Working on something similar targeting macOS on Apple Silicon, Unsloth split GGUF, compressed partial residency in unified memory (would make more sense on 128GB instead of my 64GB...), native Metal kernels, and RAM-only native compressed KV. Happy to put on GitHub when it's ready.
I was actually just working on the same thing as this, but I went down the route of mmapping the entire model into memory to avoid the extra ram usage. I also had Claude implement Medusa[1] on the model to try and avoid loading an additional model into memory but still get the benefits of MTP. Currently at a stop light so I can't list everything and I didn't get to read your full post either yet.
To expand since I just got home, I'm making all of my modifications to llama.cpp, the goal was to eventually put this on a SBC of some kind with an nvme to handle the mmapped files. I think the theoretical limit of my current setup is about 1.8 tok/s based on prior testing but that is also with the additional medusa heads not fully trained (I honestly don't know if the counting it's generated tokens or not.)
In the end it seems like the idea we had is similar, I just don't know how to write an llm parser/runner from scratch yet and instead of specifying what needed to stay in memory I just let the linux kernel handle it.
Oh last note, I also capped llama.cpp usage to 16GB of my 32GB, so it might be possible to get it down even lower.
I've taken a similar strategy w/ image/video gen at https://github.com/cretz/thinfer (see video branch for a ton of work).
Basically I kept needing an inference engine that could stream weights in and out as needed in an LRU manner. So I ended up vibe coding this thing that accepts a `--vram-budget` and stays under it (mostly). It turns out moving mmap'd bytes in and out of VRAM is way cheap compared to compute. Coupled with some pipelining/double-buffering, I almost always end up compute bound not memory bound. Granted I use way smaller models heh.
The best ideas are the ones that seem obvious. This is one of those ideas.
Excuse my ignorance. Could one just say, "One expert is all I can handle" and strip the others from the model?
was lucky enough to snag the Olares One from Kickstarter just before this whole AI induced memory chip price gouging started.
specs are Intel Core Ultra 9 275HX (24 Cores, 5.4GHz),96GB of DDR5 5600MHz RAM, NVIDIA GeForce RTX 5090 Mobile GPU with 24GB of GDDR7 VRAM, 2TB NVMe PCIe 4.0 SSD.
going to see if I can wring at least 5 tok/s.
Pretty cool! I've also been playing around with GLM 5.2 this week and was equally impressed. At work we're running it locally on some crazy expensive hardware as a test before starting another project so it's great to see people taking this massive FOSS model release and running it on an average machine, even if it's not terribly practical at this point.
Nice work!
The page has an SSD wear warning [0] I use desktop PCs that I build from components so I can replace the SSD, but what do users with soldered SSD do? Just avoid these applications or forge ahead disregarding the possible early burnout of their storage? They must use external storage as the burner SSD.
Yeah this idea makes instant sense. Very well done, this deserves a github star on concept alone.
This sort of thing is a lot of fun.
I've been going smaller.. I have a custom-quantized Rust port of DiffusionGemma (26B) that seems to perform better (in responses) than benchmarks seemed to indicate and reasonably fast for its model size. Works really well on a 36GB mac as well for both prefill and generation.
It's been interesting learning about the balance of factors for performant metal kernels on unified memory.
Should have a repo up on github in the next few weeks.
I just learned about Gemma4.pas at the beginning of this week. Now this. This make me wonder how can inference engines could be built that easy. I'm not knowledgeable in this, but I thought it would take very deep Mathematic and system level knowledge, ... and a lot of patience.
This is something that would benefit from Intel Optane memory. Too bad it was killed at the time.
How much time is spent interfacing between userland and the kernel? Can you try to get it to run as a kernel module? :)
Also in case your CPU is old enough, did you try disabling CPU bug mitigations?
I love it but where do you find that NVMe SSD for less than the price of an h100 fan let alone the memory
I'm not fully understanding this business of MoE so please forgive me if this is a dumb question, but would it be possible to use MPI with a small cluster to distribute the load?
Curious for what an MTP only result would look like, both in terms of output quality & tk/s ?!
I am curious if it's possible to adjust this to use more RAM, as i've got a machine with 64GB RAM and 24GB VRAM. Or perhaps I could run Gemma/Qwen on the GPU and have GLM-5.2 delegate smaller tasks to it. It might take some retraining of GLM-5.2
I'm also curious if you can speed this up by using many disks in parallel to increase bandwidth.
>SSD Wear Warning
> Cold starts are heavy on random reads (~11 GB/token). Reads themselves are safe, but the OS page cache can generate writes. Heavy use may accelerate wear on cheaper SSDs. Use with caution and monitor your drive health.
Hmm, maybe a safe way to do this would be to make a separate partition for the model weights, and set them to read-only? Not sure how the page cache works, if it's like per partition or per disk. If it's per disk, maybe you could have a read-only data.iso formatted as a partition and mount it as a disk?
I wonder if you could replicate this in a Colourful GeForce RTX 50-series GPU, they ship it with 2 NVMe drive slots.
I wonder how would a RAID0 array of either disks or even nvme improve the performance of this.
Question to the OP, have you tested this on a machine where the entire model and context fit in RAM ?
Your coding style is halfway to IOCCC. I'm just jealous though :)
Another recent project that runs a huge model on a 48gb Mac is https://github.com/danveloper/flash-moe - it gets over 5 tokens/sec on an M3 Max compared to this projects very impressive 1 token/sec on an M5 Max. So for anyone wanting to tackle a Mac only version that targets lower spec machines this looks like a good candidate with plenty of room for speedups [edit: because it doesn't use the gpu].
Not hijacking anything as this project is amazing.
This is great, well done! I love seeing people run things where they weren't meant to be run.
related and possibly more general purpose https://github.com/t8/hypura
[dead]
[flagged]
[flagged]
[flagged]
My main question is whether when put into practical use, this can be measured in tokens/second, or more like 1 token per minute... I have seen locally hosted LLM that are as slow as 1 tok/second still be very useful if you give it a project to do something overnight and metaphorically walk away from it, check back with what it has done in 6 or 8 hours.
0.05 to 0.1 tok/s on the other hand, as reported in the URL for the lowest class of hardware, isn't really usable for much.
edit: I think this is a fantastic project in general concept, and look forward to seeing more efforts towards the general idea of being able to run a 350B to 900B size model locally, even if as slow as 1 tok/s, on hardware that ordinary people can afford. Anything along the general concept of "we have fast read NVME SSD storage, we have a big ass model on local disk, we'll read it at 11GB/tok as we need it, not try to load the whole thing".