Slow Powerbooks

[bobw]

MacFixIt reports on some Powerbook models, G4/12" and some others slowing down.

To check what speed your machine is running at, type the following in Terminal;

sysctl hw.cpufrequency

it should show;

hw.cpufrequency: 533333332

where 53333332 would be the speed of your machine.

To reset the CPU back to top speed, required a reset of the Power Management Unit (PMU) and a reboot.

 

[Zammy-Sam]

this means 533mhz clock speed or is it another measure?
I got a tibook 1Ghz and got 667000..
So, this means my tibook is at 667mhz? Pffffffff

 

[bobw]

The 533 is just an example. If you have a 1GHz and get 667, then your machine is running slow. Reset the Power Manager then check it again.

 

[Zammy-Sam]

thought it was due to the reduced mode for the cpu, but even on highest I get the same score. Weird..
Is that command trustful?

EDIT: But hey, if my cpu is running slower, could that be the reason I have a good duration? Now I got a problem. If my duration will decrease after the PMU.. I think I would rather keep it this way. The speed is sorta ok for me..

 

[bobw]

I tried it on my 400 and it showed the correct speed.

 

[Giaguara]

I get hw.cpufrequency: 999999997 .. for a 1 GHz thing .. should I reset cpu and reboot?

 

[bobw]

Gia

Can't hurt, but you're showing the correct speed for your model.

 

[Giaguara]

nah, I think it has slowed down 000000003 hz

 

[bobw]

 

[OrganLeroy]

To reset the CPU back to top speed, required a reset of the Power Management Unit (PMU) and a reboot.

How do you reset the PMU?

 

[Zammy-Sam]

How do you reset the PMU?

What book do you have? It's different from book to book.. The tibooks PMU switch is under the keyboard lid in the top-right corner.

 

[bobw]

Resetting the PMU on a PowerBook G4 12" can be accomplished by the following process:


Shut down the PowerBook.

Press the Shift, Option, Control, and Power keys simultaneously

Wait 5 seconds

Start the PowerBook via the power key


http://docs.info.apple.com/article.html?artnum=14449

 

[ElDiabloConCaca]

Be advised that resetting the PMU frequently is strongly advised against. Plus, certain reports state that this value is simply a string stored in a file, and not an accurate representation of the current processor speed.

http://www.macfixit.com/article.php?story=20040407041919408

 

[evildan]

Also be sure to plug in your laptops before issuing the command. If I remember correctly, some powerbooks clock-down the processor when disconnected from external power source in order to prolong battery life.

 

[Zammy-Sam]

Well, I resetted the PMU but nothing changed. It still reports 667...
Either the method to measure is really faulty, or my apple store fooled me really bad

 

[heathpitts]

same here I still get hw.cpufrequency: 533333332 on a powerbook 12" after resetting the PMU. Is my PB faulty?

 

[Zammy-Sam]

I don't think so. Read the article Diablo posted. This method just seems to not be that trustful..