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View Full Version : OS X & and its EIST (un)support




meme1255
Jul 16, 2012, 08:21 AM
Hello,
I am making small research about EIST support in OS X - please, insert in Terminal this commands :
sysctl hw.cpufrequency_min
sysctl hw.cpufrequency_max
sysctl hw.cpufrequency

and post here what it prints.

Thank you ;)

My example:

MBP:~ Martin$ sysctl hw.cpufrequency_min
hw.cpufrequency_min: 2530000000
MBP:~ Martin$ sysctl hw.cpufrequency_max
hw.cpufrequency_max: 2530000000
MBP:~ Martin$ sysctl hw.cpufrequency
hw.cpufrequency: 2530000000



meme1255
Jul 16, 2012, 01:28 PM
Could someone post her/his result here? :(

Mal
Jul 16, 2012, 01:52 PM
2300000000 for all three commands.

jW

meme1255
Jul 16, 2012, 01:57 PM
Well... Thank you ;)

It really looks like Apple DOES NOT use CPU-Powersaving technologies.. WHY?!
(Or the terminal is lying, but i don't think so)

appletechpro
Jul 16, 2012, 06:04 PM
Well... Thank you ;)

It really looks like Apple DOES NOT use CPU-Powersaving technologies.. WHY?!
(Or the terminal is lying, but i don't think so)

I think you are mistaken, and I wouldn't read too much into those sysctl values -- the newer CPUs obviously have TurboBoost and are advertised by Apple as such:

http://ark.intel.com/products/52219/Intel-Core-i7-2630QM-Processor-(6M-Cache-up-to-2_90-GHz)

EDIT: I included that information to illustrate that OS X obviously supports frequency scaling, but upon further review it appears there is conflicting information on the 'net. Wikipedia states SpeedStep support has been built-in the Darwin kernel since OS X Tiger, but there don't appear to be any recent confirmations of SpeedStep actually being utilized by Apple and the sysctl values in OS X are not modifiable.

My guess is that OS X had SpeedStep support built-in to the kernel for good measure, and it probably hasn't been utilized by Apple in most of their products or possibly even at all.

meme1255
Jul 17, 2012, 04:05 AM
It looks like Tiger supported it, but then it was removed ( and XNU don't contain speed step support, so Wiki is not accurate.)

meme1255
Jul 17, 2012, 05:38 AM
Appears like SL don't support EIST, too :(

hw.cpufrequency_min: 2530000000
:confused::eek: