Glossary/Thermal/Cooling capacity
Cooling capacity
Cooling capacity is how many watts of heat a cooling system can move at a given temperature difference, setting the ceiling on sustained performance.
Also known as cooler capacity, heat dissipation capacity
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.
Capacity is a rate, expressed in watts at a stated delta over ambient. A cooler rated for 200 W at 50 °C delta will hold a 200 W chip at 70 °C in a 20 °C room. It is set by the whole chain: die-to-heatsink interface, heatsink mass and fin area, airflow through the fins, and the case's ability to exhaust that air.
The weakest link governs. A 360 mm radiator in a case with no intake path performs like a much smaller cooler because it recirculates its own exhaust. Likewise, an excellent cooler with poorly applied paste is limited at the interface, not at the fins. Upgrading the wrong link buys nothing.
SystemCheck measures the performance outcome rather than watts. If your CPU decay is steep, the cooling chain is not keeping up with the heat your chip produces, though a low OEM power limit produces the same signature, so confirm with a package-power reading before buying a cooler. A shallow decay means capacity is adequate for that load.
Related terms