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Why your local LLM feels dumber than it is

forum.level1techs.com

151–160 of 233 posts

Re: Why your local LLM feels dumber than it is

#152
Somewhat off topic, but I've started wondering if we can actually make local LLMs feel smarter than the frontier closed models, by post-training it for your specific use case.

Say Company X has a software product which consists of a million lines of code, including a ticket for every bug and new feature for this piece of software. Then wouldn't it make sense to try using an open weight model but post-train it on that specific code base while using the tickets to teach the model about past bugs and features. Not sure exactly how, but it could involve doing reinforcement learning solving a past bug on that historic version of the code base, and rewarding the model if it comes up with the correct solution (as defined by the linked PR which fixed the bug).

So essentially post-training your local open-weight model using reinforcement Learning with Verifiable Rewards (RLVR) on your software products history of bug reports and their ultimate solution. And the same for new features.

Re: Why your local LLM feels dumber than it is

#153
The problem is benchmarking. Not everyone has a 500k token workstream of the model they are setting up for the first time to run it against 10 different config and compare differences.

And if you download benchmarks from the net they are likely poisoned by models being trained on them.

Re: Why your local LLM feels dumber than it is

#154
I have been using open source LLMs locally for the past 5 months like Qwen, Llama, DeepSeek and others, and I have also noticed that current local models feel significantly dumber than closed source commercial models like ChatGPT, Claude, and Gemini. One main reason I think is the amount, variety, and quality of original authentic data on which they are being trained on, and also the training method plays a significant role in the performance difference between local open source models and closed source commercial models.

Re: Why your local LLM feels dumber than it is

#156
It is good that someone is having such a deep look. This is not exclusive to LLMs in the least. Every non-trivial program depends on hundreds of little details being correct.

That is also why I recommend including health checks in such programs. Some function that checks that all assumptions hold. That could be an endpoint, an automated test, a periodic diagnostic job, etc...

Re: Why your local LLM feels dumber than it is

#157

I saw some guy streaming how he was deploying qwen3.8 37B on his local setup. Well, he was asking Claude to do it. It took him two hours of passing errors to Claude for the endpoint to start working, he then started testing it against DS4 Flash when Qwen had thinking disabled and Claude messed up sampling parameters, it was an absolute pain to watch

Wow. I tried to get Qwen3.8 4B to parse song lyrics and analyse them. Getting ollama running was a minute or two. However coming up with a prompt that didn't turn out total garbage was impossible. After wasting over an hour and I ended up getting Qwen side by side with Llama 3.2 3B, just to see if I was being stupid. Nope, it just looks like Llama is orders of magnitude better at this specific task for some reason).…

> Nope, it just looks like Llama is orders of magnitude better at this specific task for some reason

This is almost every ML model, if the task isn't part directly or indirectly of the datasets they use for training it, then the model is gonna be pretty trash at it. What the big AI labs have over the smaller labs, is a huge amount of data and diverse set of tasks, hence they generalize better, but still not great.

So, how do you avoid having to spend hours on figuring out if the model is just dumb, or don't know the task? Your own private benchmarks! Figure out a way, ideally without using another LLM, to score how good a model is at doing your specific task. Come up with 3-5 examples for this benchmark yourself, ask a SOTA LLM to fill out 45 more, review everything VERY closely, then use this whenever you want to figure out if $new_model actually is an improvement over what you use today, and once you have a bunch of different tasks, you'll see that all these HUGE improvements tend to be specifically for the benchmarks they mention in the press release, as many of your own benchmarks won't show that big of a difference in reality.

Yes there is a higher upfront cost, but if you're building longer-term projects that rely on LLM models, particularly local ones that seem very benchmaxxed a lot of the times, you need a quick and reproducible way of scoring them somehow, where you can just add more models to compare, and you need to keep these benchmarks to yourself.

Re: Why your local LLM feels dumber than it is

#159

I just got qwen 3.8 27b mlx running on my Macbook Pro and honestly I’m pretty blown away by how not-dumb it is.

That's funny, I downloaded the same model on my 48GB M4 Pro and gave it a problem to solve in an existing codebase, it spun its wheels for twenty minutes and then fell over dead. This was using LMStudio and pi as a harness; I never use pi for anything else, so maybe I'm holding it wrong.

Maybe giving pi more output by setting higher value to maxTokens will resolve his issue

Re: Why your local LLM feels dumber than it is

#160
post #152

Somewhat off topic, but I've started wondering if we can actually make local LLMs feel smarter than the frontier closed models, by post-training it for your specific use case. Say Company X has a software product which consists of a million lines of code, including a ticket for every bug and new feature for this piece of software. Then wouldn't it make sense to try using an open weight model but post-train it on that…

You could do this for sure but its quite a lot of effort and a normal software stack is quite well known due to the massive amount of github projects and other opensource code.

You can also get a lot out of a harness in this case or your Agents.md or Claude.md file by just enhancing the context.

You might even question yourself if you are doing something wrong if a modern LLM really struggles with your code.

We do the finetuning only on small semantic data were it helps a lot.

I'm still wondering when we see smaller models (faster and cheaper) for more specific stacks like spring boot + java + angular + english only or so. Interstingly enough, i assumed LLMs are really good in any language but it seems that non english languages do reduce the ooutput quality of an LLM. At least last years GTC there was a talk about it.

There are companies though which ahve this exact problem with programming languages you normally don't see. ABAP for example is a very well known SAP language.

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