Quick Answer

An RTX 5090 throttling after a Windows update is usually a reverted power plan or a swapped driver, not a thermal limit. Windows often resets the plan to Balanced, which caps clocks, and may replace your NVIDIA driver. Set the plan to High Performance, reinstall the latest Game Ready driver, and confirm the GPU hotspot stays under 90C. Those three checks restore full 5090 clocks for most builds.

Two Kinds of Throttling

Throttling means the card is deliberately lowering clocks, and there are two causes. Power/plan throttling happens when Windows or a driver reset caps the power limit; clocks sit low even when temps are cool. Thermal throttling happens when the hotspot crosses about 90C; clocks drop as temps rise. An overlay showing clocks plus hotspot tells you which one you have in seconds.

Fix Power-Plan Throttling

After an update, open Power Options and select High Performance (or Ultimate Performance). In the NVIDIA Control Panel, set Power management mode to Prefer maximum performance. Reinstall the current Game Ready driver if Windows swapped it, since a generic driver caps the 5090's clocks. Confirm the power limit slider in Afterburner is at 100%.

Fix Thermal Throttling

If clocks drop only as the hotspot climbs past 90C, it is heat. Improve case airflow with two 140mm front intakes (around R200-R400 each at Evetech), set an aggressive fan curve, and clean dust filters. A mild undervolt cuts 40-60W and a few degrees, which keeps a 575W 5090 below the throttle point under sustained 4K load.

FAQ

How do I tell power throttling from thermal throttling?

Watch clocks and hotspot together. Low clocks with cool temps mean a power-plan or driver cap; low clocks with a hotspot near 90C mean heat. Fix the matching cause.

Did the Windows update lower my power limit?

It often resets the Windows power plan to Balanced, which caps boost clocks. Switching to High Performance and setting NVIDIA to prefer maximum performance restores them.

Will an undervolt stop thermal throttling?

Yes, usually. A careful undervolt holds the same clocks at lower voltage, cutting 40-60W and several degrees so the hotspot stays under 90C. FPS loss is negligible.

TIP

update, set the Windows power plan to High Performance and NVIDIA to Prefer maximum performance. If clocks still drop near 90C hotspot, add intake airflow or apply a mild undervolt.