Metrics

How every number is computed is docs/03_METRICS.md — the source of truth; the user's side is Read your results. The calculators are in src/FrameLedger.Domain/Metrics, and the frame-generation ladder in src/FrameLedger.Application/Recording.

The basics

• Frame time — present to present, timed with the performance counter at the moment the game presents, per swap chain. A paused or interrupted stretch is a gap, and gaps are left out of every figure.
• Average FPS — frames divided by the time measured, never the mean of instantaneous rates.
• 1% low / 0.1% low — 1000 divided by the 99th / 99.9th percentile of the game's own frame times. They need at least 1,000 / 10,000 frames; with fewer, N/A.
• Stutter — a frame longer than twice the median of the 19 frames centred on it.

The rules for showing a number

• N/A means not measured. Never 0, and never an estimate (docs/02_SPEC.md, FR-4.9).
• Frame generation is never folded into one number (rule 6). Measured: Native → Displayed (×N FG), for example 62 → 118 FPS (×1.9 FG). Not measured: Presented FPS, with a chip saying whether a frame-generation runtime was loaded — the word Native never stands alone. A session whose frame generation changed shows the state that lasted longest, always with its share: ×1.9 FG · 75%.
• Ray tracing, path tracing, ray reconstruction are Yes, No or N/A, each with where it came from (measured, the user's override, the game's default). Ray tracing is Yes on acceleration-structure builds or DispatchRays; No needs a capable device, the hook in place and no activity at all. Path tracing has no signature in the API, so it is only ever suggested.
• Tier 1 and Tier 2 are never averaged together. A query and a chart split by tier; comparing across tiers asks the user first.

The game's memory and the sensors

• The game's video memory and RAM are read from outside the game, as Task Manager shows them, once a second, in both tiers.
• The PC's sensors come from three layers (Windows, LibreHardwareMonitor, NVAPI); what a layer cannot read is N/A. GPU held back exists on NVIDIA cards only. CPU temperature needs the agent elevated and PawnIO installed.

What is still unmeasured, or measured on one machine only, is in LIMITATIONS.md and legal/ACCURACY.md.