The RTX 4090 24GB has about 5% more memory bandwidth (1,008 vs 960 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 5% faster on the RTX 4090 24GB. The RTX 6000 Ada 48GB fits more of the catalog at Q4/8K — 39 vs 33 of 61 models (48 vs 24 GB VRAM). Largest model that fits the RTX 6000 Ada 48GB but not the RTX 4090 24GB: Qwen3-Coder-Next (79.7B). MSRP is $1,599 for the RTX 4090 24GB vs $6,800 for the RTX 6000 Ada 48GB. 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 4090 24GB posts the higher tok/s in 38 rows vs 9. Methodology.