Ryzen AI Max 390 64GB vs RTX 4090 24GB for Local LLMs
The RTX 4090 24GB has about 369% more memory bandwidth (1,008 vs 215 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 369% faster on the RTX 4090 24GB. The Ryzen AI Max 390 64GB fits more of the catalog at Q4/8K — 41 vs 35 of 69 models (48 vs 24 GB VRAM). Largest model that fits the Ryzen AI Max 390 64GB but not the RTX 4090 24GB: Qwen3-Next-80B-A3B-Instruct (81.3B). MSRP is $1,300 for the Ryzen AI Max 390 64GB vs $1,599 for the RTX 4090 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 (51 shared models), the RTX 4090 24GB posts the higher tok/s in 50 rows vs 1. Methodology.