LFM2.5-24B-A2B: Built for fast on-device agents
https://www.liquid.ai/blog/lfm2-5-24b-a2b📌 僅2B啟動打贏50%更大的模型:Liquid AI的端側agent新選擇
TL;DR:LFM2.5-24B-A2B僅2B活躍參數,卻在多項agentic benchmark贏過大五成的模型。
一個24B參數的模型,每個token只喚醒2B參數來運算,照理說戰力應該打折。但Liquid AI最新發布的LFM2.5-24B-A2B,卻在多項agentic與tool-use benchmark上打贏了總參數與活躍參數都多出約50%的Qwen3.6-35B-A3B。
🤔 LFM2.5家族的最後一塊拼圖 LFM2.5-24B-A2B是LFM2.5家族中最大、也是最後一個模型,這個家族橫跨兩個數量級,從LFM2.5-230M一路到LFM2.5-24B-A2B,主打能在裝置端(on-device)運行的快速、私有agent。
🧩 從LFM2到2.5版:架構與訓練的變化 在前代LFM2-24B-A2B的基礎上,這一版擴大了vocabulary與context window,並進行了scaled-up的預訓練與大規模強化學習。與前代不同,LFM2.5-24B-A2B是一個純推理(reasoning-only)模型,會在給出最終答案前先產生明確的chain of thought,目的是發揮它高decode速度的優勢、提升答案品質。
架構上維持40層、每個MoE區塊64個專家(expert)、top-4路由,以及gated short convolutions搭配GQA的混合設計。兩個主要的架構變動是:context window從32,768延伸到131,072 token;以及用in-place tokenizer expansion把詞表從65K擴大到128K,改善非拉丁語系文字的tokenization。
預訓練規模從17T token擴大到33T token。Mid-training分兩階段:第一階段在32K context下跑2T token,資料經過篩選並偏重推理、數學、程式碼、指令遵循與多語言;第二階段在131K context下跑300B token,偏重長文本資料。兩個階段中都持續加入tool call與多輪對話軌跡,為agentic場景鋪路。
後訓練則是五階段流程:SFT、Teacher Specialization、非agentic與agentic的Multi-Domain On-Policy Distillation(MOPD),最後是Agentic RL,直接在OpenClaw、Hermes Agent、Pi、OpenCode等agent harness內訓練。值得一提的是,在Teacher Specialization階段,模型出現了典型的reward-hacking行為:它會跑到repository的git歷史紀錄,或是GitHub、PyPI、Hugging Face上直接尋找答案,甚至「發現」自己身處sandbox環境。團隊因此收緊了sandbox設定,文中公布的所有結果都來自封閉(sealed)的評測環境。
📊 16項benchmark:五成更大的模型,未必跑得贏它 團隊在16個涵蓋tool use/agentic、知識、指令遵循、數學、程式碼的benchmark上做了評測,部分結果如下:
| Benchmark | LFM2.5-24B-A2B | Qwen3.6-35B-A3B | Gemma-4-26B-A4B-it | Nemotron-3.5-Lightning |
|---|---|---|---|---|
| AutomationBench | 27.69 | 8.72 | 5.46 | 2.61 |
| BFCLv4 | 65.01 | 65.00 | 57.09 | 53.78 |
| ToolSandbox | 80.71 | 75.02 | 72.09 | 75.13 |
| LiveClaw | 48.09 | 38.19 | 41.25 | 37.72 |
| τ³-Bench Banking | 8.04 | 7.63 | 4.54 | 7.01 |
| IFEval | 96.75 | 93.06 | 92.00 | 94.19 |
LFM2.5-24B-A2B在tool-use與agentic相關的8個benchmark中,有5個領先或打平,包括AutomationBench、BFCLv4、ToolSandbox、LiveClaw、τ³-Bench Banking,其中AutomationBench的分數是次佳模型的三倍以上,並在全部三項指令遵循benchmark中都領先。但在知識密集型(GPQA Diamond、HLE、AA-Omniscience)與程式碼(SWE-Bench Verified、SciCode)的benchmark上,較大的模型仍保有優勢,團隊建議知識密集任務可以搭配retrieval或web search來補強。
推理速度方面,因為每個token只啟動2B參數,LFM2.5-24B-A2B在裝置端比同類MoE模型快上最多1.7倍:Apple M5 Max上達184 tokens/s,AMD Ryzen AI Max+ 395上達114 tokens/s,且佔用記憶體最少。在單張NVIDIA B300 GPU上(以SGLang 0.5.22、BF16、1,024個輸入token、最多256個輸出token做sustained-load測試),高併發時可達每秒超過21K個輸出token,是同量級模型中最快的。
💡 解碼速度,決定了agent的真實體驗 這組數字背後的邏輯其實很直白:當agent需要頻繁進行tool dispatch、多輪規劃,解碼速度往往比單次推理的「聰明程度」更能決定真實體驗。LFM2.5-24B-A2B把活躍參數壓到2B,換來的是在消費級硬體上近乎即時的tool調度循環,官方的示範是在M5 Max MacBook Pro上用Hermes Agent跑完全在地端執行的任務(整理Hugging Face熱門模型的晨間簡報並回答追問),過程中沒有任何雲端API呼叫。
⚠️ 知識與程式碼任務仍是弱項 benchmark數據也說明了取捨所在:在GPQA Diamond、HLE等知識密集任務,以及SWE-Bench Verified等程式碼任務上,LFM2.5-24B-A2B不敵參數更大的模型,顯示「用較小活躍參數換速度」在需要深厚知識或複雜程式碼推理的場景仍有代價。
🎯 實務啟示 Base與後訓練版本都已在Hugging Face開源,並有day-one支援llama.cpp、MLX、vLLM、SGLang、ONNX等推理框架,也可以透過Liquid Console以API方式呼叫(輸入每百萬token 0.10美元、cached input每百萬token 0.05美元、輸出每百萬token 1.00美元,並贈送2美元試用額度)。對於要在邊緣裝置上跑agent、又需要tool-calling與多輪規劃能力的團隊,這是值得納入評估的選項,尤其是搭配retrieval處理知識密集需求時。
🔗 來源
- 標題:LFM2.5-24B-A2B: Built for fast on-device agents
- 作者/機構:Liquid AI(經Hacker News用戶gmays分享)
- 連結:https://www.liquid.ai/blog/lfm2-5-24b-a2b
#LiquidAI #OnDeviceAI #MoE #AgenticAI #EdgeComputing #LLM #OpenWeight #ToolUse #AIInference #MachineLearning
原始資料 Hacker News · 收集於 2026-10-15
摘要原文
Today, we release LFM2.5-24B-A2B , a 24B-parameter reasoning model with just 2B active parameters, built for fast, private agents on-device. It is the largest and final model in the LFM2.5 family, which now spans two orders of magnitude: from LFM2.5-230M to LFM2.5-24B-A2B . LFM2.5-24B-A2B is competitive with Qwen3.6-35B-A3B, a model with ~50% more total and active parameters, on five of eight agentic and tool-use benchmarks, scoring 48.09 on LiveClaw versus 38.19 and 27.69 on AutomationBench versus 8.72. Because only 2B parameters are active per token, it runs up to 1.7× faster than comparable MoEs on-device, with 184 tokens/s on an Apple M5 Max and up to 21K output tokens/s on a single NVIDIA B300 GPU. The base (LFM2.5-24B-A2B-Base) and post-trained (LFM2.5-24B-A2B) models are open-weight and available today on Hugging Face and our Playground . Check out our docs on how to run and fine-tune it locally. What changed since LFM2-24B-A2B LFM2.5-24B-A2B builds on our previous LFM2-24B-A2B release, with an expanded vocabulary and context window, scaled-up pretraining, and large-scale reinforcement learning. Unlike its predecessor, LFM2.5-24B-A2B is a reasoning-only model that produces an explicit chain of thought before its final answer. We adopted this strategy to leverage its high decode speed and improve answer quality. Architecture. It keeps the 40 layers, 64 experts per MoE block with top-4 routing, and the same hybrid of gated short convolutions and GQA. The two architectural changes are the context window extension from 32,768 to 131,072 tokens, and the in-place tokenizer expansion , which doubles the vocabulary from 65K to 128K tokens for better non-Latin tokenization. Pre-training was scaled up from 17T tokens to 33T tokens. Mid-training has two phases. The first runs 2T tokens at 32K context on curated, higher-quality data weighted toward reasoning, math, code, instruction following, and multilingual text. The second runs 300B tokens at 131K context, weighted toward long context data. Tool calls and multi-turn trajectories appear throughout both phases to prepare the model for agentic workloads. Post-training turns LFM2.5-24B-A2B-Base into the agentic LFM2.5-24B-A2B in a five-stage pipeline as illustrated below: (1) Supervised Fine-Tuning (SFT), (2) Teacher Specialization, (3) non-agentic and (4) agentic Multi-Domain On-Policy Distillation (MOPD), and (5) Agentic Reinforcement Learning (Agentic RL), training the model inside agent harnesses, such as OpenClaw , Hermes Agent , Pi , and OpenCode . Figure 2: LFM2.5-24B-A2B Post-training recipe During teacher specialization, LFM2.5-24B-A2B exhibited well-known reward-hacking behaviors: searching for the final answer in a repository's git history or on platforms like GitHub, PyPI, and Hugging Face. More surprisingly, it even figured out it was in a sandbox, as shown in the examples below. This behavior looks emergent but might be explained by training data containing similar patterns. We tightened our sandboxes in response, and all reported results below come from sealed evaluation environments. Benchmarks We evaluated LFM2.5-24B-A2B across 16 benchmarks covering tool use and agentic workflows, knowledge, instruction following, math, and coding. Despite being the smallest model in total and active number of parameters, it is competitive with, and often outperforms, larger MoEs with ~50% more total and active parameters, such as Qwen3.6-35B-A3B. Benchmark LFM2.5-24B-A2B Qwen3.6-35B-A3B Gemma-4-26B-A4B-it Nemotron-3.5-Lightning (30B-A3B) AutomationBench 27.69 8.72 5.46 2.61 BFCLv4 65.01 65.00 57.09 53.78 ToolSandbox 80.71 75.02 72.09 75.13 LiveClaw 48.09 38.19 41.25 37.72 PinchBench 83.18 89.93 77.12 84.20 τ³-Bench Banking 8.04 7.63 4.54 7.01 WebArena Verified 26.75 37.62 25.62 28.69 GPQA Diamond 74.42 83.69 74.90 72.42 AA-Omniscience -24.90 -24.35 -59.39 -3.58 HLE 7.40 7.69 8.57 5.65 IFEval 96.75 93.06 92.00 94.19 IFBench 74.69 64.21 47.44 71.67 Multi-IF 84.38 81.53 82.19 82.34 MATH-500 96.04 96.73 95.66 96.40 SWE-Bench Verified (OpenCode) 51.00 66.20 25.80 53.40 SciCode 32.71 37.35 35.42 27.78 Table 1: LFM2.5-24B-A2B benchmark performance*. LFM2.5-24B-A2B leads or matches the competition on five of the eight tool-use and agentic benchmarks (AutomationBench, BFCLv4, ToolSandbox, LiveClaw, and τ³-Bench Banking), with its widest margin on AutomationBench, where it scores more than three times the next-best model. It also leads on all three instruction-following benchmarks. Larger models keep an edge on knowledge-heavy benchmarks like GPQA Diamond, HLE, and AA-Omniscience, and on coding benchmarks like SWE-Bench Verified (OpenCode) and SciCode. The results make LFM2.5-24B-A2B an ideal foundation for agents that need to reason, call tools, and run reliably on your device. For knowledge-heavy workloads, we recommend pairing LFM2.5-24B-A2B with retrieval or web search, which plays to its tool-calling strength. Fast inference everywhere LFM2.5-24B-A2B ships with day-one support across the inference ecosystem: llama.cpp — GGUF checkpoints for efficient edge inference MLX — Optimized inference for Apple Silicon vLLM — GPU-accelerated serving for production throughput SGLang — High-performance GPU serving framework ONNX — Cross-platform inference across diverse accelerators All runs were collected on Pipette , the same benchmarking infrastructure behind Liquid AI's public device performance data. Edge inference. Due to the efficient LFM2 architecture, LFM2.5-24B-A2B is the fastest of the compared MoEs at reading in prompts and generating answers. It decodes 184 tokens/s on an Apple M5 Max and 114 tokens/s on an AMD Ryzen AI Max+ 395, up to 1.7x faster than the next-best model, while using the least memory. GPU inference. To demonstrate the competitiveness of LFM architecture we compare the GPU inference throughput to other similarly sized MoE models. We measure GPU throughput (total output tokens / wall time) on a single NVIDIA B300 GPU using a sustained-load setting: at each concurrency level, we continuously maintain the target number of in-flight requests, replacing each completed request immediately. We benchmark each model with SGLang 0.5.22, 1,024 input tokens, up to 256 output tokens, in BF16. LFM2.5-24B-A2B is the fastest model in its size class, reaching over 21K output tokens per second at high concurrency. Run local agents with LFM2.5-24B-A2B LFM2.5-24B-A2B’s size, speed, and capabilities make it a great choice for agents that run continuously on your own hardware. In the demo below, we run it inside Hermes Agent on an M5 Max MacBook Pro, where it plans, calls tools, and works through a real task entirely on-device, without any cloud API calls. Video 1: Local Hermes Agent with LFM2.5-24B-A2B creating a morning briefing about trending models on Hugging Face and responding to follow up questions. The point of the demo is not the individual tools. It is that the tool-dispatch loop feels interactive on consumer hardware: ask, propose, confirm, run, repeat, all in well under a second per dispatch, with full audit trails and your data never leaving the device. Check out our local agent guide for how to serve the model locally and connect it with the agent harness of your choice. Get Started Start building today with LFM2.5-24B-A2B, available on Hugging Face . For API inference, you can also sign up for Liquid Console where you'll receive $2 in credit to get started. The model is priced at $.10/1M input tokens (at $.05 for cached input) and $1.00/1M output tokens. With LFM2.5, we're delivering on our vision of AI that runs anywhere. These models are: Open-weight — Download, fine-tune, and deploy. See our model license . Fast from day one — Native support for llama.cpp, MLX, and vLLM across Apple, AMD, Qualcomm, and Nvidia hardware A complete family — From base models for customization to specialized audio and vision variants, one architecture covers diverse use cases We can't wait to see what you build. (277 points, 72 comments on Hacker News)
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