The new RX 7900 XTX versus RTX 4070 Ti SUPER comparison covers the practical 24GB Radeon versus 16GB CUDA buying decision.
Capacity changes the 32B path
The official Qwen2.5-32B Q4_K_M file is 19.9GB—3.9GB larger than a 16GB pool before overhead, but with 4.1GB of raw margin on 24GB. Q3_K_M leaves an unsafe 0.1GB on 16GB versus 8.1GB on 24GB. Runtime workspace, context and KV cache still count.
Software and power matter
The Radeon requires a verified ROCm combination; the 4070 Ti SUPER may be more usable for CUDA-only applications. Reference board power is 355W versus 285W, but those figures do not establish measured efficiency. Use the CUDA versus ROCm checklist, 16GB buyer hub, 24GB buyer hub, or fit calculator.
Contribute a fair comparison
Stage both exact hardware starters, hold the artifact and workload constant, and report fallback, offload, peak memory and wall power. Or watch both families privately without replacing saved criteria until explicit Save.