MacBook Pro M3 Max 128GB vs RX 7900 XT 20GB for Local LLMs
The RX 7900 XT 20GB has about 100% more memory bandwidth (800 vs 400 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 100% faster on the RX 7900 XT 20GB. The MacBook Pro M3 Max 128GB fits more of the catalog at Q4/8K — 47 vs 32 of 61 models (128 vs 20 GB VRAM). Largest model that fits the MacBook Pro M3 Max 128GB but not the RX 7900 XT 20GB: DeepSeek-V4-Flash (158.1B). MSRP is $4,199 for the MacBook Pro M3 Max 128GB vs $899 for the RX 7900 XT 20GB. 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 (46 shared models), the RX 7900 XT 20GB posts the higher tok/s in 40 rows vs 6. Methodology.