Thermal throttling
Automatic clock-speed reduction when a CPU or GPU hits its thermal limit. Protects silicon from damage but cuts performance — often the single biggest gap between spec-sheet and real-world results.
When a CPU or GPU hits its junction temperature limit (typically 95–110 °C), firmware drops the clock to bring temperature back down. Repeated thermal throttling shows up as falling frame rates in long gaming sessions or extended Cinebench runs.
Common causes
- Undersized cooler for the TDP.
- Dried thermal paste (3+ year-old laptop).
- Dust-clogged intake.
- Ambient temperature far above typical office (gaming in a hot room).
How to spot it in reviews
Compare a chip's first-minute and tenth-minute scores on a sustained load. A drop of 20%+ signals thermal throttling. Top-tier ultrabooks with thin chassis often throttle hard; gaming laptops with vapor chambers hold their boost much longer.
In comparisons
Two laptops with the same chip can differ by 30%+ on sustained workloads purely because of cooling design. The spec sheet won't reveal this — only review benchmarks will.