RFD 2133: The pool rents from the spot book, gated on requirements first
Problem
Pool generation wants days of GPU that the desk card should not give up: the 3090 is the interactive seat for rigging and judging, and a batch that owns it for two days stalls the critical path it feeds.
Decision
Rent single RTX 4090s from the vast.ai book, requirements before price. A qualifying host carries CUDA at 12.8 or newer, 100 GB of allocatable disk, 32 GB of RAM, and 200 Mbit/s down; the measurements behind each gate are in DETAILS.md, with the price distributions that show what the gates cost. The gates exist for the cheap unqualified boxes: the sub-15-cent listings that flicker through the book bought their price with 52 GB disks and 16 GB hosts, and a model pull over a starved link is paid idle time.
Interruptible is the planning tier, near 20 cents per hour at the qualified p25; on-demand is bought when a qualified outlier dips, and sub-floor outliers were measured living minutes, not hours. Pool work is seed-checkpointed, so an interruption costs one pull.
The RunPod teardown rule applies unchanged: results are pushed when produced, the instance is destroyed after use, and the destruction is double-checked. The API key lives in the user environment, read from the password manager, never in a repository or a transcript.