Glossary/Thermal/Thermal headroom

Thermal headroom

Thermal headroom is the gap between a component's current temperature and its throttle point, which determines how long it can sustain boost clocks.

Also known as temperature headroom, thermal margin

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.

Headroom is what boost algorithms spend. A chip 30 °C below its limit will boost aggressively; one 3 °C below it will not. This makes headroom, not absolute temperature, the quantity that governs how a machine behaves at any moment.

Headroom shrinks over the course of a session as the case, cooler, and ambient air all warm. It is why the same machine performs differently at the start of a work session and three hours in, and why a benchmark result depends on whether you ran it cold.

SystemCheck cannot report headroom in degrees. It measures the behavioural consequence: how much throughput falls across a sustained run. A shallow decay means you had headroom to spare through the run; a steep one means you exhausted it. For a degrees-based reading, use a hardware monitor alongside.

Related terms

Throttle pointThe throttle point is the temperature at which a chip begins reducing clocks to protect itself, commonly 95-105 °C on CPUs and 83-90 °C on GPUs.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 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 Cooling capacityCooling capacity is how many watts of heat a cooling system can move at a given temperature difference, setting the ceiling on sustained performance.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

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