Yokemate of Keyboards
Posts: 2495 from 2006/3/21
From: Lake Shastina,...
It's possible to disable the unused second CPU in Open Firmware with the following commands:
setenv boot-args cpus=1
That should save your electricity bill a few quid and lower the temperature a bit too. :)
Has anyone confirmed that this actually lowers power consumption when running MorphOS on a dual G5 PowerMac? I read in another thread that even though the 2nd CPU can be disabled for use by the OS and software, it does not prevent it from using the same amount of electricity, or producing heat.
If it actually can be turned off and saves electricity and heat production, I will definitely use these commands on my dual 2.7GHz G5. I am not sure how to test this, and don't have an amp meter to check the amount of power being used before and after these commands are executed to run MorphOS.
Even without the 2nd G5 CPU disabled using these commands, I wonder if both G5's ramp up to the same operating speed, when any MorphOS software demands more computing power from the one G5 CPU it is accessing? I would guess that the 2nd G5 remains at an idle speed constantly while running MorphOS, but again, I have no way to test and confirm this guess.
MorphOS - The best Next Gen Amiga choice.