Meta announced today the launch of Muse Spark Open, an 816-billion-parameter open-weight AI model designed for coding and agentic tasks. The company stated that Muse Spark Open is the "most capable U.S. open-weight model to date." A notable aspect of this release is Meta's collaboration with Apple to optimize the model for Apple Silicon, enabling it to run on M5 Ultra Mac Studios.
The Muse Spark Open model can operate locally on a desktop by linking two Apple M5 Ultra Mac Studios equipped with the latest MLX framework. Each M5 Ultra Mac Studio can support up to 512GB of unified memory. When two machines are connected, they provide a combined memory capacity sufficient to host the entire 816-billion-parameter model, which has a memory footprint of approximately 493GB in its 4-bit quantized version. This setup effectively allows the two Mac Studios to function as a single system with a terabyte of unified memory.
Apple's MLX framework, an open-source array framework, utilizes the unified memory architecture of Apple Silicon to facilitate local inference and fine-tuning. This enables developers to run advanced AI models directly on their hardware. Meta CEO Mark Zuckerberg acknowledged Apple's software engineering leads, including John Ternus, for their work in optimizing Muse Spark Open for Mac Studio.
Muse Spark Open is a sparse mixture-of-experts (MoE) model that activates approximately 42 billion parameters per token. It features a 1-million-token context window and supports multimodal input, including text, image, video, and audio. Meta indicates the model excels at extended tasks, multi-step reasoning, and software engineering. Demonstrations have shown Muse Spark Open modifying iOS applications, fixing bugs, and controlling video editing software like DaVinci Resolve.
The ability to run large AI models locally offers organizations the option to maintain sensitive data and source code on-premises, rather than relying on external cloud services. This collaboration between Meta and Apple is notable, given their historical competitive relationship. Alexandr Wang, Meta's AI chief, commented on the unexpected partnership, highlighting the appeal of running AI on user-controlled hardware. Wang also stated that Meta has no visibility into how developers use the model locally, addressing potential privacy concerns.
While the 512GB Mac Studio with the M5 Ultra chip has not yet been released, it is expected later this month. The model's weights are available for download from platforms such as Hugging Face, Amazon SageMaker AI, Google Cloud Model Garden, and Microsoft Foundry Models. Muse Spark Open is free to download and comes with a license permitting limited commercial use.