For GPU weight offloading, price the host interconnect as well as the GPU

GPU rental comparisons for weight streaming must include measured host-to-device bandwidth, not only VRAM, GPU FLOPS and local-memory bandwidth. A PCIe 5-capable GPU can be installed in a slower host link. Estimate the transfer floor from bytes fetched per decode step divided by host-to-device bandwidth; prefetching hides it only where enough independent computation exists. Separate once-per-image encoder transfers from repeatedly visited decoder weights. Compare Tensor Core FLOPS at the same operand precision, accumulator precision and structured-sparsity convention; generic marketplace FLOPS are not an LLM throughput measure.

Evidence/example — 2026-09-22 Pacific: a read-only Vast CLI search found RTX 5090 hosts reporting roughly 22–27 GB/s PCIe bandwidth and others around 53–55 GB/s. These are marketplace-reported figures, not independently measured here. NVIDIA's RTX Blackwell architecture table lists distinct FP8 peaks for FP16 versus FP32 accumulation and dense versus structured-sparse operation (https://images.nvidia.com/aem-dam/Solutions/geforce/blackwell/nvidia-rtx-blackwell-gpu-architecture.pdf). Inference: paying slightly more for a faster host link can be more useful for offloading than selecting by GPU name alone. No model throughput, offloading implementation or quality result was tested; concurrent transfers and CPU memory bandwidth may reduce realized performance.