In a Training Loop 🔄

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Stefan Schweter PRO

stefan-it

https://schweter.bayern

AI & ML interests

Flair Library 💕, NER & PoS Tagging, LM Pretraining (mostly encoder-only & encoder-decoder), Historical Language Models, German Language Models, Bavarian NLP 🥨

Recent Activity

reacted to martinsu's post with 🔥 27 minutes ago

I wasted days on a GPU node on a bug that shouldn't exist So I was fine-tuning TildeOPEN-30B and the outputs were... weird. Token ID 179 (<0x00>) kept appearing between almost every token pair. Took me a bit to figure out what was going on. Turns out I used the fast tokenizer for training, but the model was trained on the slow one. Silent failure. Well... long story short—TGI uses (forces) the fast tokenizer, no questions asked. And you'll have agile's kryptonite: silent failure. If the model was trained on slow, it's a silent disaster. I got curious and wrote a quick script to check how common this is. Ran it on 6,014 LLM HF models overnight. Roughly 10% of HF model downloads have mismatched tokenizers. Not all mismatches are catastrophic, but some are brutal — like chat template markers inflating from 1 token to 3, silently wrecking context windows and causing model act weird. This wasn't rigorous research, but the drift is real. And the worst part? 968 models(out of 500+ downloads) have both fast and slow tokenizers present, but they still produce different outputs. No missing files, no errors — just silent degradation. TGI defaults to the fast tokenizer, as does AutoTokenizer.from_pretrained(). If a fast tokenizer doesn't exist, it auto-generates one. If your model was trained on slow, you get silent degradation. Output looks fine; the model just performs worse. Sometimes really worse. You'd never know. If model was trained on fast tokenizer, its fine, but how do You know? The root cause? Either model authors run HF conversion and upload both without verifying, or users run TGI, which always forces(converts to) fast . The result of this fight with tokenizers is https://huggingface.co/martinsu/tildeopen-30b-mu-instruct It's based on TildeOPEN-30B (a solid EU HPC multilingual base). Nothing fancy—just a proper instruction fine-tune where I didn't mess up the tokenizer this time. Full article: https://github.com/martins-u/tokenmagedon

liked a model 4 days ago

Cognitive-Lab/NetraEmbed

liked a model 4 days ago

Cognitive-Lab/ColNetraEmbed

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Wohoo 🥳 I have finished my 2025 GPU workstation build and I am very excited to train new awesome open source models on it.

I built my last GPU workstation 5 years ago featuring an AMD Ryzen 5900X, 64GB of G.SKILL Trident Z RGB on an ASRock X570 Taichi cooled by an Alphacool Eisbär 420. GPU was a Zotac RTX 3090 AMP Extreme. Unfortunately, I was never satisfied with the case - some Fractal Define 7, as it is definitely too small, airflow is not optimal as I had to open the front door all the time and it also arrived with a partly damaged side panel.

For my new build, I've used the following components: an outstanding new AMD Ryzen 9950X3D with 64GB of Corsair Dominator Titanium (what a name). As a huge Noctua fan - warm greetings to my Austrian neighbors - I am using the brand new Noctua NH-D15 G2 on an ASRock X870E Taichi in an amazing Lian Li LANCOOL III chassis. One joke that only NVIDIA Blackwell users will understand: you definitely need a tempered glass panel to check if your GPU cables/connectors start melting 😂 And the best is yet to come: I returned my previously bought Zotac RTX 5090 Solid to the eBay seller (because of... missing ROPs, only NVIDIA Blackwell users will again understand) and bought a Zotac 5090 AMP Extreme INFINITY (yes, the long name indicates that this is the flagship model from Zotac) from a more trustworthy source (NBB in Germany).

I am so happy to start training and fine-tuning new open source models - stay tuned!!!

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