What is thermal throttling, and how do you fix it?

Thermal throttling is when your CPU or GPU gets too hot and deliberately slows itself down to avoid damage — and your frame rate drops with it. It's a built-in safety feature, not a fault. The classic sign is a game that runs fine for a few minutes, then the fans roar and the FPS sags. The good news: it's almost always fixable, usually for free.

This one matters to us for a specific reason. Our calculators estimate the frame rate your parts can deliver running at full speed — a throttling PC quietly performs below that. So if your real numbers are lower than the estimate, heat is one of the first things to check.

What is thermal throttling?

Every modern processor has a built-in temperature ceiling. When its internal sensors see the chip approaching that limit, it automatically lowers its clock speed and voltage to cut heat output — "when the temperature hits a critical point, the system adjusts the performance down" (Corsair). Lower clocks mean fewer frames per second. The chip is choosing slower-but-safe over fast-but-cooking, which is exactly what you'd want it to do — it's just costing you performance in the process.

How do I know if my PC is throttling?

The tell-tale pattern is performance that starts strong and fades. Watch for:

• FPS that drops after 5–15 minutes of play, once everything has heated up — not from the first second.
• Fans spinning up loud, then micro-stutters creeping in.
• Clock speeds falling while temperature climbs toward 90–100°C under load. That combination confirms it.

To see it for yourself, run a free monitor like HWiNFO or MSI Afterburner's overlay and watch clock speed and temperature together during a demanding game. If the clocks dip every time the temperature spikes, you've found your culprit.

What temperatures are actually safe?

Here's where people panic unnecessarily. Modern chips are built to run hot, and a high number under load is usually fine — throttling only kicks in near the very top. Rough guide:

Desktop GPUs generally start throttling around 90°C (MakeUseOf). One important nuance: AMD's recent Ryzen 7000 and 9000 CPUs are designed to run right up to 95°C and hold it there to extract maximum boost. On those chips, seeing 95°C isn't a warning sign — it's the CPU working as intended. Throttling that hurts you is when temperature is high and clocks are dropping below the chip's rated speed.

What causes it?

Throttling is a cooling problem at heart — the chip makes more heat than the cooler can move. The usual causes, roughly most common first: dust clogging fans and filters; poor case airflow; dried-out thermal paste on an older system; a cramped or hot room; or an aggressive overclock pushing more heat than the cooler was sized for. Laptops are especially prone to it because there's so little room for cooling.

How to fix thermal throttling

Start with the free, low-risk fixes and only escalate if you need to:

• Clean the dust. Blow out fans, filters, and heatsinks. This is the single most common fix and costs nothing (Corsair).
• Improve airflow. Tidy cables, make sure intake and exhaust fans aren't blocked, and don't box the PC into a sealed cabinet.
• Set a better fan curve in your motherboard BIOS or GPU software so fans ramp up sooner.
• Undervolt. Lowering the voltage feeding your CPU or GPU can cut temperatures by 5–15°C with little or no performance loss — one of the best-value tweaks there is.
• Repaste — carefully. Fresh thermal paste helps an older CPU a lot. On a GPU it's riskier (it can void the warranty and damage the card), so leave a working graphics card alone unless it's old and overheating despite good airflow.
• Upgrade the cooler if you're still throttling after all of the above, or cap your frame rate to lower the sustained load.

Why throttling makes your real FPS lower than the estimate

This is the honest caveat behind every frame-rate number, ours included. A calculator works out what your CPU and GPU can do at their rated speed. A chip that throttles isn't running at that speed, so you get less — and no amount of rebalancing your parts will recover it, because the bottleneck isn't your hardware pairing, it's heat.

So if the FPS calculator says one thing and your game says noticeably less, check your temperatures before you blame the build or start shopping for upgrades. And if your frame rate is low but steady from the very first second, it's probably not heat — see how to fix a bottleneck for the rest of the usual suspects, or 1% lows if the problem is stutter rather than a low average.