Liquid AI Releases LFM2.5-VL-3B-DSpark Model
Liquid AI launches LFM2.5-VL-3B-DSpark featuring speculative decoding for vision-language models, achieving up to 3.13x faster decoding.

Stock photo for illustration only, not from the actual event
- Liquid AI releases LFM2.5-VL-3B-DSpark for vision-language models
- Speculative decoding accelerates text generation by up to 3.13x
- Model weights are live on Hugging Face in Safetensors and GGUF formats
- Day-one support available in SGLang, MLX-VLM, and llama.cpp
Liquid AI has officially released its new LFM2.5-VL-3B-DSpark model, bringing speculative decoding to vision-language models (VLMs) and achieving up to 3.13x faster decoding speeds. Labeled as an experimental release, the model ships under the LFM Open License v1.0, permitting free commercial use exclusively for companies with under $10 million in annual revenue. Weights are publicly available on Hugging Face in both Safetensors and GGUF formats.
While standard models generate a single token per forward pass, speculative decoding introduces a small drafter model that proposes multiple tokens ahead. The larger target model then verifies the entire block in one pass, retaining agreed tokens. DSpark follows the design recipe from Liquid AI's text-model drafters, reading hidden states from several layers of the target model to predict the next k tokens.

Stock photo for illustration only, not from the actual event
A key architectural advantage is modality-agnostic design. By the time tokens reach hidden layers, both text and image patches are processed simply as tensors, enabling Liquid AI to reuse the exact same inference algorithm for its vision-language model. The drafter itself is a simplified attention-only model utilizing 4 layers and a block size of 9, with Liquid AI recommending a block size of 8 or 9 depending on hardware, and Apple Silicon runs utilizing a block size of 8.
Training utilized supervised fine-tuning data covering common vision-language tasks over 10 epochs, with all ablations and training executed exclusively on AMD hardware. Evaluation followed the MMSpec benchmark across six task categories: General VQA, Text VQA, Image Captioning, Chart VQA, Complex Reasoning, and Multi-turn Conversation, running at batch size 1, temperature 0, and 16-bit weights.
Context Analysis: Speculative decoding targets the generation bottleneck in large language and vision models by using a lightweight drafter to predict tokens, which the main model verifies in parallel. However, image encoding and prefill phases run at standard speeds, meaning total performance gains remain bounded by Amdahl's Law on edge devices where prefill constitutes a larger share of latency.
Peak speedup figures derive from distinct tasks; for instance, the 3.13x decoding boost on the M5 Max stems from COCO captioning, whereas the 2.62x end-to-end gain comes from MMMU-Pro. Under higher concurrency tests on a single H100 using SGLang, DSpark maintained throughput advantages across all measured levels.
Users can deploy the model immediately with SGLang v0.5.19 or newer by launching LiquidAI/LFM2.5-VL-3B with --speculative-algorithm DSPARK. On Apple Silicon, MLX-VLM v0.7.2 or newer accepts the drafter via --draft-model, while llama.cpp pairs the GGUF drafter directly with the LFM2.5-VL-3B-GGUF target. Integration work is currently public via respective repository pull requests.
Source: MarkTechPost
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