Hy
(question at the bottom, information at the top)
I found a way to:
§ limit the number of active cores
§ disable hyper-threading
(this might be very useful for some developers
and for those who want to save some extra battery life)
Things you'll need to do:
§ install Xcode (it's in the Mac App Store)
§ open Instruments (just type it into you spotlight)
§ open the preferences of Instruments (⌘ ,)
§ you'll see the option to limit the number of active cores and to disable hyper-threading in the "General" section
quick tips:
§ don't use this if you have a dual core (there's really no battery gain)
§ disabling hyper-threading will increase your battery life (but will reduce your system performance)
(I don't recommend you to disable this if your goal is to increase battery life.
OS X won't use hyper-treading if you're not using much cpu power and some other variables,
you'll see what I mean if you watch you're cpu usage in the activity monitor
(double click on the graph if you want to see all you're cores (+virtual cores)))
§ play with the settings as you like and use coconutBattery (or something similar) to see your battery power usage (only on battery)
I got a 2.6GHz quad core (Ivy Bridge) and using a single core
(with hyper-treading, so 2 cores (1 virtual, 1 real)) I get 1 hour more battery life
please note:
§ the processor cores which have been disabled be enabled again after sleep/wake or system restart.
§ changing the number of active cores doesn't actually turn off any processor cores.
Instruments only tells the system not to schedule work on the cores that are made inactive.
(which basically means that the disabled cores will run at there lowest speedstep and therefor uses less power)
this is the link for the 2nd way:
(note: the first way they describe is (I guess) outdated, use my way I described above, it does the same thing)
http://developer.apple.com/library/mac/#qa/qa1141/_index.html
Now, the second way is using the command line to change the boot-arguments in the NVRAM
(follow the above link and you'll find out how)
I didn't tested the 2nd way yet.
But if anyone does,
please say so in the comments below.
Now, finally the question:
Does anyone knows if you disable core's that way, it'll turn off processor cores?
(and actually will be using 0 power)
(question at the bottom, information at the top)
I found a way to:
§ limit the number of active cores
§ disable hyper-threading
(this might be very useful for some developers
and for those who want to save some extra battery life)
Things you'll need to do:
§ install Xcode (it's in the Mac App Store)
§ open Instruments (just type it into you spotlight)
§ open the preferences of Instruments (⌘ ,)
§ you'll see the option to limit the number of active cores and to disable hyper-threading in the "General" section
quick tips:
§ don't use this if you have a dual core (there's really no battery gain)
§ disabling hyper-threading will increase your battery life (but will reduce your system performance)
(I don't recommend you to disable this if your goal is to increase battery life.
OS X won't use hyper-treading if you're not using much cpu power and some other variables,
you'll see what I mean if you watch you're cpu usage in the activity monitor
(double click on the graph if you want to see all you're cores (+virtual cores)))
§ play with the settings as you like and use coconutBattery (or something similar) to see your battery power usage (only on battery)
I got a 2.6GHz quad core (Ivy Bridge) and using a single core
(with hyper-treading, so 2 cores (1 virtual, 1 real)) I get 1 hour more battery life
please note:
§ the processor cores which have been disabled be enabled again after sleep/wake or system restart.
§ changing the number of active cores doesn't actually turn off any processor cores.
Instruments only tells the system not to schedule work on the cores that are made inactive.
(which basically means that the disabled cores will run at there lowest speedstep and therefor uses less power)
this is the link for the 2nd way:
(note: the first way they describe is (I guess) outdated, use my way I described above, it does the same thing)
http://developer.apple.com/library/mac/#qa/qa1141/_index.html
Now, the second way is using the command line to change the boot-arguments in the NVRAM
(follow the above link and you'll find out how)
I didn't tested the 2nd way yet.
But if anyone does,
please say so in the comments below.
Now, finally the question:
Does anyone knows if you disable core's that way, it'll turn off processor cores?
(and actually will be using 0 power)