The RTX 5090 32GB has about 78% more memory bandwidth (1,792 vs 1,008 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 78% faster on the RTX 5090 32GB. The RTX 5090 32GB fits more of the catalog at Q4/8K — 38 vs 33 of 61 models (32 vs 24 GB VRAM). Largest model that fits the RTX 5090 32GB but not the RTX 4090 24GB: Mixtral-8x7B-Instruct-v0.1 (46.7B). MSRP is $1,599 for the RTX 4090 24GB vs $1,999 for the RTX 5090 32GB. 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 5090 32GB posts the higher tok/s in 41 rows vs 6. Methodology.