Still working on replacing and/or controlling fan speeds in my MDD dual G4 PowerMac to reduce fan noise and I cam across this:

http://www.xlr8yourmac.com/feedback/MDD_CHUD_feedback.html

I thought some of you might want to read it and see if any of the linked information is useful to you in creating a quieter computing experience.

Is there any code in MorphOS2.7 (or 3.0) that controls the speed of the fans in a G4 PowerMac, or do the fans just run at full rpm all the time while running MorphOS?

With my dual 1.42 the CPU fan was noisy at quiet and very noisy on medium, you don't want to know about full.

It also made this horrible clunky ball bearing knocking noise as well, not that loud, but it was very annoying..

I replaced it with a silenx fan, unfurtnatly the '14db 60CFM' fan didn't seem to cool enough, '18db 90 cfm' was a little noisy on full until I reduced the voltage using zalman fanmate when I could get volume as low as possible while still having good cooling.

If you enable CPU ” Nap Mode” in MacOS X you get that rather irritating squeek that you also get on dual G5s, but the cooling is dramatic, the CPU runs cooler than the hard drives! You need an older version of CHUD tools, the exact version I'll check on later.

Last thing, on MorphOS, which of course only uses 1 CPU dosn't have a temperature gauge, but if you go back into MacOSX the temperature is low, so I think that MorphOS is fine as regards CPU overheating.

@amigadave
my opinion: nap mode is useful in Sonnet Encore/MDX dual G4@1600/1800 CPU cards for PowerMac MDD/FW800
I have a new silent PSU in PowerMac Fw800 dual G4@1420 and no problems; you can also change the PSU with an ATX http://atxg4.com/mdd.html

I'd like to have a temperature utility in MorphOS3.x for PowerMac G4 and PowerBook G4