Reference baseline (dev box — what the low-end box is compared against)

Release build, AMD iGPU dev box, post-cull (2-scene) standalone, 1080p, steady state (measured 2026-07-22, diagnostics.log, ~5.5 min run):

Metric	Dev-box value
fps	~165 (0 dropped frames over 51k)
frame_ms avg / p99	~6.06 / ~6.9 ms
working set (rss_bytes)	~303 MB (run-to-run noisy; private commit ~338 MB is the stable figure)
gpu_bytes	~16.6 MB

The low-end box need not match these — it need only clear the ≥ 60 fps floor and report its footprint so the vendor spread is on record.