Hi Timothy, On Fri, 1 May 2009 17:59:35 -0400, Timothy Normand Miller wrote: > I've recently discovered lm_sensors, pwmcontrol, and fancontrol. > IIUC, they're all part of the same package. My CPU fan is under > automatic control by the system hardware, but the case fans were > fixed, and this system has allowed me to make the fan speeds vary with > temperature, which has made my system a LOT quieter when it's > relatively idle, yet I can launch compute-intensive apps and still > maintain a cool system. > > Anyhow, I'm running into a problem with leaving the fans off. The > fans take too long to come up to speed from stop. It's not a function > of the fans themselves; when I power the system on, the snap from zero > to full speed in less than a second. So my best guess is that > fancontrol won't just SET the duty cycle but wants to gradually ramp > it up or down. > > If I leave the fans on all the time at a setting of 100/255, then it's > okay. But if I leave them off until they're needed, it takes way too > long for the fans to even begin spinning. > > Is there a way I can control fancontrol's ramp-up rate? I wasn't able > to find anything on this in the documentation. The fancontrol script really isn't that smart. It doesn't implement any form of ramp-up, the target speed (actually, output duty cycle) is computed linearly based on the measured temperature, and applied immediately. However it is known that fans need a relatively high duty cycle to start spinning, and we do have a mechanism for that: MINSTART. I suppose you didn't set its value high enough. Probably the best is that you share your /etc/fancontrol configuration file with us and I'll tell you what I think should be changed. Please also tell us which version of lm-sensors you're running, to make sure you aren't affected by an old bug. -- Jean Delvare http://khali.linux-fr.org/wishlist.html
