controlling fan speed

[heisenberg77]

When I have the x60 on either the ultrabase or ac adapter, the fan starts spinning quite fast in defined intervals. (fan on - 1:13 min., fan off - 50 seconds). I have tried various settings in power management but this does not change anything. However if I just run the x60 on the battery the lowest power setting then it it not a problem. Has anyone else experienced this? And does anyone have a solution?

[lev]

What does task manager say your cpu usage is, during one whole 73sec/50sec cycle?

[heisenberg77]

It does not go above a few percent. So it is not due to any processes activating at specific time intervals.

[rek]

I am having the same problem with my X60s (1.66 LV Core Duo) when docked in the Ultrabase. Like the OP, this happens under no load. The system is perfectly silent until you dock it on the Ultrabase, at which point the fans will immediately ramp up to 3500rpm and off again every minute or two.

Monitoring the temperatures with TPFancontrol, there is little difference between when undocked and on battery, undocked and AC, and on the Ultrabase. It's as though something inside the computer is saying, "I'm on a dock .. I must turn on the fan"

[rek]

Downgraded the BIOS version from 2.07 to 1.10 and now in the Ultrabase the fan tends to be more consistently at 3500rpm, which is less annoying than the constant stopping and starting.

It's a case of "so close and yet so far", as it seems that when on battery and under constant high load, the fan spins at a virtually-silent 2900-3000rpm... but when docked, the lowest a spinning fan wants to go is ~3500, which is a point where starts to be clearly audible over the hard disk.

If only it stayed at 3000rpm on dock instead of 3500, it'd be perfect! (The fan control programs can't help, as they don't seem to be able to get it to go under 3500... time to try BIOS versions with different versions of the embedded controller I guess)

[rek]

After some experimentation, it appears that when docked in an UltraBase, the embedded controller forgets that the "low" fan speed exists, and when the fan is required, will ramp up the fan from "off", straight up to the higher speed levels. It'll skip the low fan speed on its way back down to silence, as well..

I tried isolating everything else and concluded that it's just the connection of the Ultrabase that does this; it doesn't matter if you're on AC or battery power, if you have anything in the Ultrabase's drive bay, or whatever power management profile you have set.

It sounds like it might be a bug; why wouldn't you want the fan speed to step up and down gracefully? It only makes the fan on/off cycle more annoying to the ear. I've submitted something to IBM to let them know this might be something that needs fixing in a future EC firmware.