alt Hacker NewsYea, this is currently the confusing part of running local models for newbies: Even after you have decided which model you want to run, and which org's quantizations to use (let's just assume Unsloth's for example), there are often dozens of quantizations offered, and choosing among them is confusing.
Say you have a GPU with 20GB of VRAM. You're probably going to be able to run all the 3-bit quantizations with no problem, but which one do you choose? Unsloth offers[1] four of them: UD-IQ3_XXS, Q3_K_S, Q3_K_M, UD-Q3_K_XL. Will they differ significantly? What are each of them good at? The 4-bit quantizations will be a "tight squeeze" on your 20GB GPU. Again, Unsloth steps up to the plate with seven(!!) choices: IQ4_XS, Q4_K_S, IQ4_NL, Q4_0, Q4_1, Q4_K_M, UD-Q4_K_XL. Holy shit where do I even begin? You can try each of them to see what fits on your GPU, but that's a lot of downloading, and then...
Once you [guess and] commit to one of the quantizations and do a gigantic download, you're not done fiddling. You need to decide at the very least how big a context window you need, and this is going to be trial and error. Choose a value, try to load the model, if it fails, you chose too large. Rinse and repeat.
Then finally, you're still not done. Don't forget the parameters: temperature, top_p, top_k, and so on. It's bewildering!
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> Say you have a GPU with 20GB of VRAM. You're probably going to be able to run all the 3-bit quantizations with no problem, but which one do you choose? Unsloth offers[1] four of them: UD-IQ3_XXS, Q3_K_S, Q3_K_M, UD-Q3_K_XL
There are actually two problems with this:
First, the 3-bit quants are where the quality loss really becomes obvious. You can get it to run, but you’re not getting the quality you expected. The errors compound over longer sessions.
Second, you need room for context. If you have become familiar with the long 200K contexts you get with SOTA models, you will not be happy with the minimal context you can fit into a card with 16-20GB of RAM.
The challenge for newbies is learning to identify the difference between being able to get a model to run, and being able to run it with useful quality and context.
To add more complexity to the picture, you can run MoE models at a higher quant than you might think, because CPU expert offload is less impactful than full layer offload for dense models.
HuggingFace has a nice UI where you can save your specs to your account and it will display a checkmark/red X next to every unsloth quantization to estimate if it will fit.
We made Unsloth Studio which should help :)
1. Auto best official parameters set for all models
2. Auto determines the largest quant that can fit on your PC / Mac etc
3. Auto determines max context length
4. Auto heals tool calls, provides python & bash + web search :)