Understanding GPU Frame Times

Average speed and frame pacing

Average FPS summarizes throughput across the measurement window. Frame intervals reveal how evenly frames arrive. A run with a good average can still contain visible pauses. Around 16.7 ms per frame corresponds to 60 frames per second, but the browser can pace callbacks to the display refresh cycle.

Percentiles and slow frames

The p50 interval is the median; p95 and p99 describe the slow end of the recorded distribution. Lower intervals are better for an otherwise matching workload. The 1% low FPS summarizes the slowest portion of sampled frames. Short runs provide fewer samples and make tail statistics less reliable.

Consistency is not hardware health

Consistency is derived from recorded timing variation. Late-run slowdown compares earlier and later portions of one run. Neither is a temperature measurement or proof of thermal throttling. Look at the full trace and repeat the run before attributing a change to the graphics card.

Keep the measurement context

Compare equivalent settings and the actual API. Keep the tab visible and close unrelated graphics work. A frame interval includes browser behavior; a GPU timer describes a different quantity. An unavailable GPU measurement is not zero. Export the report so another person can see the method and samples.

• Open GPU Benchmark
• GPU Testing Methodology