Adjust fan voltage?

[sergej99]

I am quite annoyed by the sound my fan makes. But recently when coming back from hibernation, on the lowest possible fan speed, the fan only ran at 2600 rpm, which was really pleasant. It was still audible, but seemed like most of the annoying high pitch noise caused by the fan, which is normally there (at 2900 rpm, which is usually the lowest speed) was gone.

All that was according to tp fan control. I guess some voltage fluctuation caused this behaviour. Does anybody know if there is a way to change the speed of the fan? Say, get the lowest speed down from 2900 to 2500? Is it possible over software? Or does anybody know if the fan is easily accessible and one could maybe put a small resistor in, to lower the voltage on the fan a bit? Or will the thinkpad controller always check for the rpm and increase the voltage till the fan runs at 2900 rpm?

I know it's hard to believe, but those 300 rpm really made the difference, now the fan is at 2900 again, and it really drives me insane. I'm gonna have to sell it if I can't change that. I don't pay that much money to have a noisy machine while idling.

[filter]

I believe darrenf could say something about this, since he has taken his T60 apart completely, looking for new features.

[gunston]

TP can take care of it.
you can set the threshold to turn on/off the fan at certain temperature levels.

[sergej99]

Yes I am fully aware of what tp fan control can do, but I want to change the rpm of speed 1. The fan turned with 2600 rpm for a short while (for whatever reason), which was acceptable, but usually speed 1 is 2900 rpm, which is too loud for me.

[gunston]

yeah, listen to music all the time..
cocksure that you won't hear anything except the playing music

[darrenf]

If you throw in just the *right* amount of dust, I think you can get the desired result.

Since the RPM of the fan is read by the motherboard, I would expect it to compensate for the effect of an inline resistor (although one could certainly be fitted there).

Just to not overlook the obvious, did you try changing the fan control setting in Power Manager? In my experience, the act of changing the fan control setting (as opposed to the setting itself) seems to have a pleasant effect on fan noise.

As a test, I just tried changing the setting and here are my results:

Fan was running at 2900RPM under "Maximize Performance"
Fan stayed at 2900RPM after switching to Balance
Switched back to Max and the fan went off for a few seconds, rolled up to 130RPM and back to off for about 30 seconds then fired up to 2900RPM.

If you want to see if a resistor might work, take the keyboard out and produce some physical resistance to the fan rotation (slight - at the hub) and watch to see if the motherboard compensates. If not, perhaps a resistor would work.

Good luck and take lots of pictures!

-darren

[astro]

Fan was running at 2900RPM under "Maximize Performance"
Fan stayed at 2900RPM after switching to Balance
Switched back to Max and the fan went off for a few seconds, rolled up to 130RPM and back to off for about 30 seconds then fired up to 2900RPM.

Hey Darren, I think I figured out why this setting seems illogical: it is the way they have worded it.

The Power Manager considers "temperature" one of the "parameters"... So "Balance all parameters" means run the fan often to keep temps down. If only they considered "noise" a parameter as well.

"Maximize Performance" probably means maximise the performance of the battery, as the fan obviously has no other effect on the performance of the laptop.

[gunston]

agreed!

[darrenf]

I've just been ignoring the wording, assuming that it means something in Chinese!

-darren

[christopher_wolf]

I am quite annoyed by the sound my fan makes. But recently when coming back from hibernation, on the lowest possible fan speed, the fan only ran at 2600 rpm, which was really pleasant. It was still audible, but seemed like most of the annoying high pitch noise caused by the fan, which is normally there (at 2900 rpm, which is usually the lowest speed) was gone.

All that was according to tp fan control. I guess some voltage fluctuation caused this behaviour. Does anybody know if there is a way to change the speed of the fan? Say, get the lowest speed down from 2900 to 2500? Is it possible over software? Or does anybody know if the fan is easily accessible and one could maybe put a small resistor in, to lower the voltage on the fan a bit? Or will the thinkpad controller always check for the rpm and increase the voltage till the fan runs at 2900 rpm?

I know it's hard to believe, but those 300 rpm really made the difference, now the fan is at 2900 again, and it really drives me insane. I'm gonna have to sell it if I can't change that. I don't pay that much money to have a noisy machine while idling.

That is quite a difficult thing to do; the applied voltage states are controlled by the EC, the EC is told what the system wants the fan to do. TP FCU simply interfaces with the WinIO driver, which then talks to a HAL, which then goes to the EC and sets the registers to the state that is desired and that the EC understands; to my knowledge, there is no ability to gain direct control over the voltages applied to the fan via software unless you go and do it manually. There is a lower bound supported by the EC, but it is different on different Thinkpads; I do not know what it is for the T60. For the X31 to X40, it is around 3700RPM to about 7350RPM.

HTH

[darrenf]

That is quite a difficult thing to do; the applied voltage states are controlled by the EC, the EC is told what the system wants the fan to do. TP FCU simply interfaces with the WinIO driver, which then talks to a HAL, which then goes to the EC and sets the registers to the state that is desired and that the EC understands; to my knowledge, there is no ability to gain direct control over the voltages applied to the fan via software unless you go and do it manually. There is a lower bound supported by the EC, but it is different on different Thinkpads; I do not know what it is for the T60. For the X31 to X40, it is around 3700RPM to about 7350RPM.

That would seem to suggest that an inline resistor would indeed lower the fan speed at states, correct? Or does the EC vary power based on RPM feedback?

-darren