... what's a good fan speed for smc fan control to set for a mac ...
I think it depends on which iMac model you have. My 20" white 2.16 GHz
has the following default fan speeds -- but I believe I've seen different
defaults for ALU iMacs. They might also be different for 20" versus 24".
ODD: default 800, maximum 5000
HDD: default 1400, maximum 5000
CPU: default 800, maximum 3600
Also, on my machine, the standard fan control algorithm increases the
speed of all three fans when the CPU temperature rises -- even if the
HDD and ODD temperatures remain the same. I have no information on
how the control algorithms would respond to high ODD or HDD temps,
but I wouldn't be surprised if all three fan speeds increased.
Here's a handy freeware app that allows you to raise the CPU temp by
adding load to the CPU. If the fans don't respond, something's wrong.
BTW, my iMac runs cool -- ODD, HDD, CPU all in the 35C to 38C range
with all fans idling near their default speeds -- so, I've had no need for
I keep my white 2.16Ghz 20" iMac at the following settings during normal use:
I pretty much got to these settings by turning the fan up the most I could before them becoming noticeable. That way it is still quiet but not idling. If I run BOINC (maxes out processors) I have another profile to kick it up to 1750/2130/2530. This is still quiet while offering much more airflow/cooling. After building a PC and overclocking, I believe in running the fans as high as you will tolerate the noise to keep the components as cool as possible to prolong longevity and maintain stability. There is a noise-to-cooling tradeoff with fans, so it is really how much noise can you tolerate vs. how much heat are you comfortable with. Hotter is not better when it comes to component life/reliability.
Just in case it hasn't been mentioned in this thread I think most of us that have SMCFanControl are also using some other application to monitor the internal temperatures as well. This helps us to determine how to set the fan speeds. This way you can see the temperature results. I use Temperature Monitor but I know a few other people use the iStat Pro widget.
Sorry to somewhat invade on this thread. I felt like it wasn't worth starting
a new thread. Should the fans brake due to using SMC Fan Control to increase the RPM would this still be covered under apple warrenty or does it void it? Also what is the recommend max speed to set the fans to. Obvious 5000 would be stupid.