Yokemate of Keyboards
Posts: 2795 from 2006/3/21
From: Northern Calif...
I have a dual 2.5GHz G5 PowerMac (early model) that has a defective G5 CPU socket on the motherboard, and it runs MacOSX on the one remaining good 2.5GHz G5 CPU without any trouble. It would make a perfect MorphOS computer, if MorphOS is ever ported to any of the G5 Mac models and this model were to be one of the models supported.
There has also been some discussion on the LowEndMac G3-G5 mailing list about running a dual G4 PowerMac with one of the two G4 CPUs clocked at the minimum speed it can run at to reduce heat production and energy use, when running an OS that can only use one of the two G4 CPUs. It was suggested that one of the two G4 CPUs could be clocked as low as 300MHz, while the other G4 was running at the full speed of 1.25GHz, or 1.42GHz (depending on which model it is). One member on that mailing list had tried over clocking a dual G4 CPU PowerMac and found out later that he had only overclocked one of the two G4 CPUs, so this shows that they can be run at different clock speeds, while still running MacOSX correctly.
I would guess that it is probably possible to down clock one of the two G5 CPUs (or possibly 2 of the 4, G4 CPU cores in a quad core, dual G5 PowerMac model), to reduce heat and power consumption, if you are only going to run MorphOS on that computer and have no need or desire to run it in a dual boot setup with MacOSX.
He suggested that I down clock one of my two 1.25GHz G4 CPUs to the minimum speed to reduce heat and energy usage, instead of trading my dual 1.25GHz G4 CPU module for a single 1.25GHz G4 CPU module.
I have decided to do the trade anyway and will overclock the single G4 CPU module when it arrives, instead of taking his advice to keep my dual 1.25GHz G4 CPU module, because I also have a dual 1.42GHz G4 CPU module to swap back to, if I decide to revert to a dual booting G4 PowerMac.
I also just found and purchased a stock Apple Copper heat sink that was provided in the dual 1.42GHz G4 PowerMac MDD FW800 models, so this heat sink will provide better cooling efficiency than my other stock aluminum heat sink, or the Tin heat sink that was originally provided on the single G4 PowerMac MDD models, or the slower speed dual G4 PowerMac MDD models. The better Copper heat sink should arrive a few days before I receive the single G4 CPU module, so I will have everything I need to install the single G4 CPU and attempt the overclocking. I think I will try running it at 1.5GHz first and see how hot it runs at that speed, before I consider trying to push it faster. I am not sure that anyone has pushed the 1.25GHz G4 CPU faster than 1.5GHz, but I was hoping to match the speed of my G4 PowerBook at 1.67GHz, but that may be asking for too much and cause trouble, or failure, and may not be worth the risk of damaging the G4 CPU.
Considering recent comments by some of the MorphOS Dev. Team members, it looks like I probably will never be able to try MorphOS on my damaged 2.5GHz G5 PowerMac that only has one recognized G5 CPU, or working G5 socket on the motherboard (I have swapped the G5's from side to side and confirmed that both G5's are working properly, because it is always the same side that does not work, so it has to be a motherboard problem that is preventing both G5's from being seen as working).
That is okay, as it is their decision and only they know how much work is involved to complete a port of MorphOS to any G5 model, so I must respect their decisions and reasons behind those decisions. As Jim has pointed out earlier. The Team has made all the right decisions so far (as far as I can tell), and I expect that they will continue to make all the right decisions in the future. They are smart guys, even if they might not be the best at marketing and promoting their work to potential users and other developers. I know that they are trying to do everything they can to make MorphOS successful and self-sustaining.
[ Edited by amigadave 12.03.2012 - 16:52 ]
MorphOS - The best Next Gen Amiga choice.