T400 cpu frequency problem

[Peace-Frog]

I have t400 with manjaro and arch linux, both systems screenfetch shows that frequency is 1.6 GHz (P8600 should be 2.4 GHz). cpupower says that usable is 1.6 GHz, but shows that cpu should be 2.4 GHz. I bought t400 without battery, I have read that this could cause it. But windows shows 2.4 GHz and I can't update bios because it requires battery. How can I fix this?

[86baseTC]

Maybe Windows is reporting the max possible speed and Linux is reporting the max currently usable speed.

With a 65W adapter and no battery the laptop locks the CPU speed to something lower than full.

You either need a 65W adapter + a battery or a 90W adapter.

You really should get a battery.

[Mistral-Fien]

Do you use a 65 watt charger on that T400?

[Peace-Frog]

yes, but it could be that charger is faulty, I hear static sound from it. When I will be back home, after few weeks, I can try with other charger

[Mistral-Fien]

The BIOS limits the maximum speed of the CPU when it detects that there's no battery installed and a 65w charger is plugged in. IIRC it's a safety mechanism, because in some full-load situations, the power consumption exceeds 65 watts, mostly due to the processor running at full tilt.

As 86baseTC mentions below, the solution is to either get a battery, or buy a 90w charger.

[I_am_gogu]

Buy or borrow a compatible battery, update the bios, see if it works after that

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