Meta has released Muse Spark Open, an 800-billion-parameter open-weight AI model optimized for Apple Silicon. Running it locally requires 1TB of RAM.
Meta calls it "the most capable US open-weight model to date." The release extends the company's work on open models. Meta has previously said it believes the US should not let Chinese labs lead in open-source AI.
In benchmarks released by Meta, Muse Spark Open outperforms GLM 5.3 and Kimi K3 on agentic tasks and visual reasoning. Those results are the company's own measurements.
Mac Studios can run the model locally
Muse Spark Open is the first model optimized to run locally on Apple's M5 Ultra-equipped Mac Studio. According to Meta, the M5 Ultra's integrated GPU can use up to 512GB of unified memory in each machine. Two 512GB Mac Studios can therefore hold the model together.
The model can also run across four 256GB M5 Ultra Mac Studios. A setup with those machines would cost roughly $38,000. That puts local use beyond the typical vibe coder's budget. For larger organizations spending heavily on AI tokens, the hardware could be appealing if the model performs as Meta suggests.
The model is available on Hugging Face
Muse Spark Open is available to download now from Hugging Face. Apple has not announced a price or specific ship date for the 512GB Mac Studio, but says it will be available in "late October."
