Mac Studio M3 Ultra 96GB vs RTX 5080 16GB for Local LLMs
The RTX 5080 16GB has about 17% more memory bandwidth (960 vs 819 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 17% faster on the RTX 5080 16GB. The Mac Studio M3 Ultra 96GB fits more of the catalog at Q4/8K — 47 vs 25 of 61 models (96 vs 16 GB VRAM). Largest model that fits the Mac Studio M3 Ultra 96GB but not the RTX 5080 16GB: DeepSeek-V4-Flash (158.1B). MSRP is $3,999 for the Mac Studio M3 Ultra 96GB vs $999 for the RTX 5080 16GB. MSRP is a launch list price, not live retail — Amazon prices move; click through for the current price. In the Q4/8K head-to-head below (44 shared models), the RTX 5080 16GB posts the higher tok/s in 36 rows vs 7. Methodology.