---------- Original message ---------- Subject: Downclock Powermac G4 mdd Date: Dienstag 24 August 2010N From: Matevž Markovič <[email protected]> To: [email protected]
> Hello! > > I have a Powermac G4 dual (1.25 ghz), running under OS X Tiger. > I use this computer as a test server with low traffic. Because no > performance-demanding tasks are running on it, I want to decrease > the temperature of both cpus and thus also reduce the noise of the fan, as > it is way too high. (and the power consumption) You have already found the following? http://coolstuff.wordpress.com/2007/02/19/powermac-g4-mdd-cooling-and-noise-reduction/ http://bitsandpieces.info/MDDG4CoolingMod.htm Installing different fans –that are more silent– seems to help a lot. > I have heard of CHUD 3.5.2 and its option of enabling nap mode, but I am > not willing to risk crashing the machine, because I have read that > enabling nap on both cores will probably crash the computer and it also > has other side-effects. Possible. But you could try it anyway, and deactivate it when you see crashes for real. > Is it possible to manually reduce the speed of both cpus? (probably from > Open Firmware). I would rather go with 2 x 1.0 Ghz (250mhz less per cpu). > And if it is, how dangerous is that? I have never heard that this would be so easy. G4 processors don't support alteration of clock speed (like modern processors do). Even the G5 Dual-Core “Late 2005” (IBM PowerPC 970MP aka Dual-Core G5) only supports to switch between full clock speed and half clock speed. You will have to go the hard way and modify the hardware. Sorry, this link is in German: http://macschrauber.de/3elektronik/3elektronik/mddxlr8.html A bad machine translation still helps to find the valued information: http://translate.google.com/translate?hl=de&sl=de&tl=en&u=http%3A%2F%2Fmacschrauber.de%2F3elektronik%2F3elektronik%2Fmddxlr8.html I'm the in the link mentioned PLL table is not for the 1.25 GHz processors, but you may give it a try anyway. If you are willing to move resistors – knowing the risks– you should be able to make a 1.25 GHz machine be a 1.0 GHz machine. Only, while this will make the G4 MDD processors run cooler for sure, the impact to noise is uncertain. Whish you good luck! Cheers, Andreas aka Mac User #330250 -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/g3-5-list
