Diagnose
A throttling test that names the kind. Power limit or heat, not just a percentage.
Throttling is the chip stepping its clock down to stay inside a limit. Which limit is the whole question, and it is written in the shape of the curve.
What the report tells you
Three figures, each with its reading.
Decay
%
Throughput lost between the warm-up and the last fifth of the run, on a curve sampled four times a second.
Kind
power / thermal
A single step is a power or current limit. A slide is thermal. The classifier states its confidence and the measurement's noise floor.
Settled level
% of peak
On a deep run, where the chip ends up and how stable that level is across three windows.
The diagnosis
The shape of the curve, read for your case.
01A single step down
Power-limit throttling. The boost window closed. Adjustable in the BIOS or the vendor's tool; not a cooling problem.
02A steady slide
Thermal throttling. The chip is stepping down as it heats. Cooling changes this curve.
03Held
No throttling within the run. On a standard run that means forty-five seconds; if you need longer, the deep run holds for three minutes.
Every class comes with a stated confidence and the measurement’s own noise floor. How the shape is read
Where a browser stops
What it cannot tell you.
- No clock speed: the browser measures throughput, so the report shows the effect of a clock change without the megahertz.
- No temperature: thermal throttling is inferred from the shape, never read from a sensor.
- Browsers round the core count and coarsen timers; the methodology page states the exact resolution used.
Which run
Standard, 3 minutes.
Forty-five seconds catches a boost timer expiring and the onset of a slide. Choose the deep run when the question is where the chip settles.
Both kinds are free. The choice is on the set-up screen.
Questions
Asked in these words.
- How do I test if my CPU is throttling?
- Run a sustained all-core load and watch throughput over time rather than a single score. If it falls after the first seconds and stays down, the chip is throttling; the shape of the fall says whether the cause is a power limit or heat. This test does exactly that in a browser tab.
- What is the difference between power-limit and thermal throttling?
- A power limit is a wattage or current ceiling set in firmware: the chip drops to it in one step once its boost window closes. Thermal throttling is the chip stepping down progressively as its temperature rises: a slide. The fixes are different, which is why the report names the kind.
- Is 10% decay bad?
- Under about 5% is normal. Around 10% on a laptop is common and usually a power limit. Above 15% with a sliding shape means cooling is the limit. The report puts the figure next to the shape so the number is read correctly.