i have a Thinkpad T410s and i have a problem with CPU Fan,

if i plug it AC Power, my CPU Fan is fast(4000rpm) , if i unplug CPU Fan is (1900rpm),

i have changed all BIOS options, but it isn't work.

Have you any advice?

without AC :

AC :

11 answers Last reply
More about tomshardware
  1. Have you checked profiles, when its plugged in the cpu is obviously running full speed creating more heat and therefore the fan is spinning faster to cool it.

    I would imaging you need to change your settings and profile for when the machine is running off mains power.

    There will be a setting in control panel not the bios, you will need to turn speedstep on in the bios though.

    Hope this helps.
  2. Do you want it to run at full speed all the time??? The low speed when not plugged is to save power in-order to prolong battery power...

    I remember seeing Speedstep in AC & Battery modes in BIOS as well as adaptive thermal management in AC & Battery modes... did you alter any of these???
  3. i cant't see speedstep.
    This is my BIOS screen :

  4. 2nd line down Intel Speedstep Technology. :ouch:

    Underneath you have your profiles for AC and battery power, MAX BATTERY.

    Also Thermal Management.

    You have them all the same so the laptop should perform the same plugged in or running on battery.
    Usually you would have battery setting to power saving or something similar.
  5. Well its there right in front of you second from the top... Intel (R) SpeedStep technology... its set for maximum in both so that cant be the case... also its balanced for both Thermal Management options...

    Do you want it to run 100% all the time - Yes or No??? If yes then change balanced to maximize performance for both options under Thermal Management... I think that should do the trick...

    SpeedStep is for changing the clock speed of the cpu automatically to meet the performance needs of the PC... It helps in minimizing or maximizing volts to the cpu along with heat generated as a result... it helps in keeping a balance if its enabled and in automatic mode... So i would suggest you keep it automatic...
  6. Hey beanoslim... it wont run the same since its "BALANCED" under thermal management... by that it'll adjust the fan's speed to preset speeds under AC and Battery (which we cant see)... There's no way of changing those presets but usually its 50% under battery...

    If you want to control fan speeds then disable thermal management and install speedfan and control the speeds as per your temp requirements...
  7. Oh right, didn't realise the balanced would have different preset settings for each power source.

    Why would you use thermal managemnet over Speedstep or vice versa then if they just about do the same thing?

    Is it because you can adjust the settings under Speedstep whereas the thermal mangement is pre-defined?
  8. Under SpeedStep the available options would be maximum performance, battery optimized, maximum battery and automatic... now the degrees of CPU speed throttling under each setting i wouldn't know... its preset by lenovo under intel specs...

    Under thermal Management the options available would be maximum performance and balanced... i guess max performance would make the fans run 100% all the time and balance would be preset values...

    It it were upto me i would just manage speeds myself through speedfan...
  9. I'll leave it to you...not the Speedfan instructions again. :lol:
  10. :p Don't worry... people are already using that post as a reference...
  11. I have. :D
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