The RX 7900 XT 20GB has about 4% more memory bandwidth (800 vs 768 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 4% faster on the RX 7900 XT 20GB. The RTX A6000 48GB fits more of the catalog at Q4/8K — 39 vs 32 of 61 models (48 vs 20 GB VRAM). Largest model that fits the RTX A6000 48GB but not the RX 7900 XT 20GB: Qwen3-Coder-Next (79.7B). MSRP is $4,500 for the RTX A6000 48GB 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 37 rows vs 9. Methodology.