Slashdot has reported:

Meta has released Muse Spark Open, an 816-billion-parameter open-weight model optimized to run locally across two 512GB M5 Ultra Mac Studios with Apple’s MLX framework. Meta calls it the “most capable U.S. open-weight model to date.” The model is designed for coding and agentic work, with 42 billion active parameters and a 1 million-token context window.

According to MacRumors, Meta says Muse Spark Open performs well on extended tasks, multi-step reasoning and software engineering. The model was tuned for Mac Studio, and Meta describes the pairing as the “best way to run a powerful model on your own desktop.”

Meta said Apple’s unified memory architecture allows the M5 Ultra’s integrated GPU to use up to 512 GB per Mac Studio, enabling two machines to hold the full model. “And the chip's 1.2 TB/s of memory bandwidth is fast enough to read the small slice each token needs,” the company said. “The result is two Mac Studios behave like one supercomputer with a terabyte of unified memory.”

Apple has not released the 512GB Mac Studio yet, but it is expected to arrive later this month. The system is likely to be costly: the 256GB Mac Studio is already priced at more than $10,000.