Muse Spark Open: Hardware, License and Cost to Self-Host
Originally published at WowHow Almost nobody should self-host Muse Spark Open: the model card asks for at least 700 GB of VRAM even in NVFP4, so for anything under billions of tokens a month the hosted endpoint at $1.25 per million input tokens is the cheaper and simpler route. Meta released the open-weight 816B-parameter mixture-of-experts model on 15 October 2026 [1] . Only 42B parameters are active per token, which helps speed but does nothing for memory: every expert still has to sit in RAM. Below: the weight arithmetic with the real file sizes, a comparison of three ways to run it, what the license says, and how Meta's benchmark numbers stack up against the reported competition. TL;DR 816B total parameters, 42B active, 1M-token context, BF16 and NVFP4 weights [2] . The BF16 repo holds 1.64 TB of safetensors across 65 shards [3] ; the NVFP4 repo is 533 GB across 127 shards [8] . The card lists 700 GB of VRAM for NVFP4 and 2 TB for BF16. Two M5 Ultra Mac Studios (up to...