Heat soak
Heat 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.
Also known as thermal saturation, soaked
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.
A cold heatsink is a heat sponge. For the first seconds to minutes of load it absorbs energy into its own mass, keeping the die cooler than steady state would allow. Once that mass reaches equilibrium, the only path for heat is out through the fins into moving air, and temperature stops improving.
Time to soak scales with thermal mass. A thin laptop soaks in under a minute; a large air tower takes several minutes; a 360 mm liquid loop can take ten or more. This is exactly why short benchmarks flatter big coolers less than they flatter small ones, and why a quick test can miss a cooling problem entirely.
SystemCheck's 60-second CPU load is long enough to move well into the soaked region on laptops and small-form-factor systems, where the practical problems live, while staying short enough that people actually finish the test. On a large tower cooler the run may end before full soak, so a very low decay figure on such a system should be read as "good through 60 seconds" rather than as proof of indefinite stability.
Related terms