Reflection 发布 501B 开源权重模型 Beam

Domain: reflection.ai Points: 94 | Comments: 25 [Top Comments] - > Beam is a sparse Mixture-of-Experts model with 501 billion total parameters, 23 billion active, built for coding, reasoning, and agentic workloads. > Beam’s capabilities come from major investments in both pretraining and reinforcement learning (RL). We pretrained the model on 23.8 trillion diverse, curated, high-quality tokens from the web and proprietary licensed datasets, matching or outperforming available similar-sized open base models. In parallel, we developed the algorithms, training environments, and infrastructure needed to sustain high-compute RL at exceptional scale. Our high-compute RL run generated over 100 million rollouts on 10.5K NVIDIA GB300 GPUs over 4 weeks of training. Early access, no weights no tech details, just a sign up here for info - And also a "proprietary data set" hahaha... Probably just means they don't want to show it, and it is data, that either they shouldn't have, or that there is nothing special about their training data and it is just meant to sound like there is some secret ingredient, while there is none. - I'm all for more open models, but talk is cheap and this is a rather pointless announcement without anything backing it up. Publish your weights and HF repo or shut up IMO. - Suppose I inherited a data center spanning several hundred acres full of GPUs and free electricity. Where do I get the data? I mean, this many models. They have to start somewhere. - Get data from Claude. That's what the Chinese (allegedly) do. - If you ask a model, they will generally tell you where to get data. Modern frontier models have the large advantage of having tens if not hundreds of millions of users providing use cases to train against to improve their responses. - I guess public datasets on HuggingFace and some shadow libraries content is enough to start. e.g. fineweb dataset is 50TB - Always glad to see more open-weight models, but this caption on the 2nd demo image had me do a double-take: "Land or Water Generalization Experiment: We recreated the viral X puzzle by asking Beam to create a fixed 180×90 grid for longitudes -179° to 179° and latitudes -89° to 89°, with 16,200 points. This puzzle is a few days old, so could not appear in the training data, thus testing the model’s generalization. Beam gets 95.5% coverage right, putting us between Opus 5 (92.5%) and Fable 5 (97.8%), which shows how well it generalizes to novel new tasks." Oof, no, this "puzzle is a few days old" is incorrect even if it's a social media trend just recently. Asking a model to generate a world map in this way is \_at least\_ from August 2025 as it appeared on LessWrong at that time: [https://www.lesswrong.com/posts/xwdRzJxyqFqgXTWbH/how-does-a...](https://www.lesswrong.com/posts/xwdRzJxyqFqgXTWbH/how-does-a-blind-model-see-the-earth) - Yeah I remember when the original post about this came out. Def not recent. Though I think their point survives in that they didn't exactly RL on this. - Am I the only one who thought of the BEAM VM after the first word of thee title? - nopes - I remember being in the room with pretraining day 1 to help monitor the training job launch. Watching this model train from day 1 has been an amazing experience! - the performance chart puts the better open source models behind the fold making it seem like it outperforms them... but it doesn't! all for open source models but this announcement is misleading - Yes. All the link made me realize is that I should checkout Deepseek 4.1 flash - very curious to see more about what kinds of hardware you can run this on and the perf. characteristics… on the face of it, it seems like optimizing for inference speed might(?) be good for running on smaller hardware, but i suppose it could be the other way around and it is actually much resource-hungrier for the number of parameters, etc. … - Bigger and still worse than existing free Chinese models that are smaller? Open weight models are nice, but at this point it seems western models are very far behind Chinese ones, despite Chinese companies publishing a lot of their findings. I hope we get more open models and more providers, as being stuck with a model from China or US with no competition is risky. Google does do a great job with Gemma models. It's one of the few language models actually good at language. OpenAI's top closed models can't even write norwegian correctly. - This appears to be larger than DeepSeek v4.1 Flash, more expensive to run, and worse on every measured metric. Am I missing something? - Beam goes brrrr - We're still at the stage where every new entrant is welcome in my opinion. Doesn't need to be record-breaking upon initial release. - Apparently there is more to making good models than copying everything on the internet. - Open model that is not yet open or widely accessible via API. Primarily comparing to non-SOTA models like Inkling and GLM 5.2. Included comparison to GLM 5.3 and DeepSeek V4.1 Flash in the table, but not in the charts (I assume they would make them look bad). Also no results from AA Index or Arena.