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Muse Spark Open ships 816B total and 42B active parameters with a 1M-token context

pytorch.org by PyTorch Team at Meta 4 min read Editor score 7/10

Meta released an 816B-total/42B-active multimodal model with a 1M-token context, optimized for SGLang and vLLM across NVIDIA, AMD, and Intel. Its scale and serving targets matter to teams evaluating open-weight models for coding and agentic work.

What

Muse Spark Open is an open-weights model with 816B total parameters, 42B active parameters, and a 1M-token context window.

How

It is optimized for SGLang and vLLM and ships Helion kernels with reported 1.03–3.95× speedups on NVIDIA GB300 versus custom hardware-specific kernels.

Why it matters

Its long context and active-parameter count are key considerations for engineers planning inference for coding and agentic workloads.

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