Thinkpads Forum

I upgraded my T420s from Windows 7 to Windows 10 at launch and for the last few days it always seems to be underclocked even on full load. I tried exporting a bunch of images from lightroom and the CPU is at 0.78 Ghz throughout. Restarts, Drivers checks and Clean boots don't seem to have an effect. It's just stuck there. Any ideas?

Chnage your profile to maximum performance and see if the CPU clock speed doesn't dip in speed as much. It will run much warmer with constant higher clock speeds.

Do you have both a working battery and a power adapter connected at the same time when this happens ?

Do you have nvidia ?
what is your power adapter rating, 90w or 65w ?

Hans Gruber wrote:Chnage your profile to maximum performance and see if the CPU clock speed doesn't dip in speed as much. It will run much warmer with constant higher clock speeds.

I just came back to take the post down, cos it was just the same. Moving to maximum performance brings the CPU back into the 2.3 to 2.53 Ghz change. looks like clean boot wasn't all that clean since the power manager was still booting in the background.

Thanks for the accurate step!

I'm still surprised that Maximum battery life would underclock constantly at 0.74 to 0.78 Ghz esp since it doesn't exactly increase battery life all that much.

Anyone manage to figure out the best settings to make the T420s usable as well as portable enough? Almost regretting choosing the 420s over the 420!

Running on a 65W adapter without a battery will also limit your cpu speed.