Glossary/CPU/Current limit throttling
Current limit throttling
Current limit throttling is a CPU cutting frequency because amperage through the voltage regulators hit a ceiling, even when temperature and wattage are fine.
Also known as EDP throttling, ICCMAX, electrical design point throttling
Not measurable from a browser
A browser cannot read temperatures, power draw, fan speed, VRAM capacity, clock frequency or native FLOPS. For a direct reading use a native monitor such as HWiNFO64, GPU-Z or lm-sensors. SystemCheck contributes the other half: whether the condition is costing you throughput, measured as decay and consistency.
Power is voltage times current, so a chip running at low voltage can hit its current ceiling well below its wattage ceiling. Intel exposes this as ICCMAX and reports it as EDP (electrical design point) throttling; AMD exposes an equivalent TDC/EDC pair. Dense vector workloads such as AVX-512 draw enormous current at modest clocks and trip this limit first.
It is the most confusing throttle to diagnose because both obvious suspects look innocent: temperature is moderate and package power sits below PL1. Only a monitoring tool that reads the throttle reason registers will name it. HWiNFO64 exposes per-reason throttling flags on Intel; Ryzen Master shows TDC and EDC utilisation as percentages on AMD.
SystemCheck will show the resulting decay in its CPU stage, since a frequency drop is a throughput drop regardless of cause. It cannot identify the cause: reading throttle-reason MSRs requires ring-0 access no browser has. Treat a SystemCheck decay figure as the detection step and a hardware monitor as the attribution step.
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