Mac Studio M2 Ultra 192GB vs RTX 3090 24GB for Local LLMs
The RTX 3090 24GB has about 17% more memory bandwidth (936 vs 800 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 17% faster on the RTX 3090 24GB. The Mac Studio M2 Ultra 192GB fits more of the catalog at Q4/8K — 50 vs 33 of 61 models (192 vs 24 GB VRAM). Largest model that fits the Mac Studio M2 Ultra 192GB but not the RTX 3090 24GB: Qwen3-235B-A22B (235.1B). MSRP is $6,999 for the Mac Studio M2 Ultra 192GB vs $1,499 for the RTX 3090 24GB. 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 (47 shared models), the RTX 3090 24GB posts the higher tok/s in 37 rows vs 10. Methodology.