Quick Answer

Thermal throttling means your CPU or GPU is hitting its temperature limit and deliberately slowing down to protect itself - usually past 90 degrees on the CPU or 83-85 degrees on the GPU. The fixes are cheap: clean dust, reapply thermal paste (around R250-R450), improve case airflow, or fit a better cooler. Throttling is why your FPS starts strong then drops 10-30 frames after 15-20 minutes of play.

How to confirm throttling

Log temps with HWMonitor or your GPU software while gaming. If clock speeds drop exactly when the CPU passes 90 degrees or the GPU passes 83 degrees, that is throttling. A healthy CPU should hold under 85 degrees and a GPU under 80 degrees under sustained load. If temps are fine but clocks still drop, suspect a power or driver limit instead.

Cheap fixes that work

Start with dust - blow out the heatsink fins and fans, especially in carpeted SA homes. If the PC is over two years old, reapply paste like Arctic MX-6 (around R250-R450 at Evetech); dried paste adds 10-15 degrees. Confirm front-to-back airflow with at least two intakes and one exhaust. These three steps clear most throttling without new parts.

When you need a better cooler

A high-end chip on a stock cooler will always throttle in long sessions. A Ryzen 7 or Core i7 wants a strong tower air cooler (around R600-R1,200) or a 240mm AIO (around R1,500-R2,500); a Ryzen 9 or Core i9 is happier on a 280-360mm AIO. For the GPU, ensure case intake feeds it cool air rather than recirculating hot exhaust.

FAQ

At what temperature does a CPU throttle?

Most modern CPUs begin throttling around 90-95 degrees and shut down near 100 degrees. GPUs typically throttle from 83-85 degrees. Keep the CPU under 85 and GPU under 80 to avoid lost performance.

Why does my FPS drop after 20 minutes?

That pattern is classic thermal throttling - temps climb during play until the chip hits its limit and slows down. Logging temps with HWMonitor confirms it; cleaning dust and repasting usually fixes it.

Will a better cooler stop throttling?

Yes, if heat is the cause. Upgrading a high-end CPU from a stock cooler to a tower air cooler or a 240-360mm AIO can drop load temps 10-20 degrees and hold clocks steady.

TIP

and temps with HWMonitor during one long session - if clocks drop exactly as temps cross 90 degrees, clean the dust and reapply paste before buying a new cooler.