Glossary/Benchmark/Peak vs sustained performance

Peak vs sustained performance

Peak performance is the best a system does in a short burst; sustained performance is what it holds at equilibrium, and the gap can exceed 30% on laptops.

Also known as burst performance, steady-state performance

Measured by SystemCheck

Part of the four-stage run: a 60-second sustained CPU load reporting throughput, decay and consistency; a memory stage reporting bandwidth and latency; a calibrated GPU raster load reporting frame time, pacing and decay; and a path tracer reporting samples per second. The paragraphs below say which metric carries this term.

Peak is a marketing-friendly number. It is real (the machine genuinely did that, briefly), but it describes a state the system can hold for seconds. Sustained is what governs every task longer than a menu animation: exports, compiles, gaming sessions, model training.

The gap is a property of the whole system rather than the chip. The same processor shows a small gap in a well-cooled tower and a very large gap in a thin laptop. That is why identical spec sheets produce different experiences and why a single headline score cannot capture a machine.

SystemCheck reports both sides. Early-window throughput represents the peak region, the settled level represents sustained, and the decay figure between them is the number that actually describes what your machine is like to use. A report showing high peak and steep decay is exactly the machine that benchmarks well and disappoints in practice.

Related terms

Sustained clockSustained clock is the frequency a processor settles at once the system reaches thermal and power equilibrium under continuous load.Read more Thermal decayThermal decay is the measurable fall in performance from the start of a sustained load to its steady state as the system heats and hits its limits.Read more Sustained loadA sustained load is a workload held long enough for the system to reach thermal and power equilibrium, revealing real behaviour rather than a boost snapshot.Read more Boost clockBoost clock is the highest frequency a CPU will reach opportunistically on a light thread count when thermal and power headroom allow.Read more Heat soakHeat soak is the state reached when a cooler and case have absorbed all the heat they can buffer, so component temperature depends only on airflow and ambient.Read more

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