The RTX 5070 12GB has about 5% more memory bandwidth (672 vs 640 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 5% faster on the RTX 5070 12GB. The RX 9070 16GB fits more of the catalog at Q4/8K — 25 vs 18 of 61 models (16 vs 12 GB VRAM). Largest model that fits the RX 9070 16GB but not the RTX 5070 12GB: gpt-oss-20b (21.5B). MSRP is $549 for the RTX 5070 12GB vs $549 for the RX 9070 16GB. 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 (40 shared models), the RTX 5070 12GB posts the higher tok/s in 25 rows vs 15. Methodology.