Thermal throttling: why your GPU slows down and how to fix it

GPUs protect themselves from heat and excess power by lowering clock speeds when limits are reached. That is called throttling. It is normal in small amounts, but significant throttling means you are not getting the performance you paid for.

How it looks in a test

Frame rate starts high and drifts down over the first minutes, then flattens. In the SMG Verdict this shows up as a low Endurance score, a falling line in the performance-over-time chart and often the Heat-Soaker persona. Run the five-minute Thermal Throttle Test: short tests finish before heat has built up.

Common causes

• Dust clogging heatsinks and fans.
• Poor case airflow or blocked laptop vents.
• Dried-out thermal paste or pads on older hardware.
• Power limits on laptops running on battery or in quiet modes.
• Ambient temperature, especially in summer.

Fixes, easiest first

1. Plug in, select a performance power mode and raise the laptop for airflow.
2. Clean fans and filters with compressed air.
3. Improve case airflow: fan placement, cable management, removing obstructions.
4. Apply a more conservative fan curve or a mild undervolt with a vendor-supported tool.
5. Repaste or re-pad only if you are comfortable opening the device and the warranty allows.

Always verify with a monitoring tool. A browser cannot read temperatures; it can only reveal that performance changed.