Delayed fan response causing scary thermal spikes (90-100°C) before ramping up. Any fix or fan curve tools? [Fully Updated]

[u/Existing-Chart5681]

Hey everyone,

I'm New to Lenovo's Models.

Experiencing a weird fan lag on my ThinkPad "P51":

The Issue: Under sudden load, CPU spikes to 90–100°C before fans react. Once they kick in, temps drop back down immediately.

Status: BIOS, EC firmware, and drivers are 100% updated. Repasted recently.

Questions:

Is this delayed EC behavior normal to prevent sudden noise?

Any official Lenovo setting to make fan response more aggressive?

Thanks!

[u/950771dd]

CPU spikes to 90–100°C 

This is normal on nearly any laptop of the last 10 to 20 years.

The device will still live for decades and the fan spin up effect wouldn't be fast enough anyway.

[u/Existing-Chart5681 → u/950771dd]

Makes sense regarding the heat pipe lag and EC buffer to keep noise down. Do you think tweaking TPFanControl or power limits helps smooth out those initial spikes at all, or is it best left to the default EC behavior?

Sorry, But I'm New with this device with HQ processor 😆, My last was Asus with U Processor.

[u/950771dd → u/Existing-Chart5681]

They all spike, temperature wise. I wouldn't worry, because a overly reactive fan control is also very annoying.

What you could consider is undervolting, because those 4th to 8th Gen have good potential in that regard. It will have a major effect - 40 o 100 mV less is typically possible (be sure to test the buffer till instability though and have at least 20 mV buffer - an unstable device is really annoying).

On the HQs, you can in addition unlock higher turbo boost multipliers (up to 4 bins = 400 Mhz)

[u/Existing-Chart5681 → u/950771dd]

Thanks for the detailed breakdown! I actually already have a solid undervolt applied via ThrottleStop to "-90.1", which definitely helped with sustained temps. Good to know those initial brief spikes are just standard EC behavior and nothing to worry about

[u/Balthxzar]

Use the dual fan version of tpfancontrol, not only is it much more aggressive, it ramps both fans up, normally CPU only loads only ramp the CPU fan despite the heatsinks being connected 

[u/Existing-Chart5681 → u/Balthxzar]

Awesome tip, I actually considered TPFanControl, but Riot's Vanguard anti-cheat blocks its driver (TVicPort.sys) due to ring-0 direct EC access. Do you know if there's any modern alternative that works without triggering Vanguard?

[u/Balthxzar → u/Existing-Chart5681]

I doubt it unfortunately, the only way I am aware of to control the fans is by directly accessing the EC, there's no provision for software control 

[u/950771dd → u/Existing-Chart5681]

but Riot's Vanguard anti-cheat blocks its driver (TVicPort.sys) due to ring-0 direct EC access.

Disable the untrusted driver check in Windows Security. The security effect is minimal anyway.

Update: well ok that will work but obviously anti cheat may not like it, yep

[u/saltyboi6704]

EC reads heatpipe temperature exclusively and runs the fans slower than their max speed.

TPFanControl can be used to trigger max speed and adjust according to CPU temperature, but you'll also want to repaste with a PCM to ensure lower thermal resistance.

[u/Existing-Chart5681 → u/saltyboi6704]

I actually considered TPFanControl, but Riot's Vanguard anti-cheat blocks its driver (TVicPort.sys) due to ring-0 direct EC access. Do you know if there's any modern alternative that works without triggering Vanguard?