[eric_woe]

Hi there - am following up on an issue that was first noted in November 2003 but as far as I can tell, was never resolved, or there was no follow up.

I have a 12 inch PowerBook G4 with 640Mb of RAM, running 10.3.3. Machine is about 9 months old.

A few reports on MacNN in November 2003 noted that these machines were running at lower CPU speeds (533 MHz) rather than top speed (867 MHz).

Typing the command

sysctl hw.cpufrequency

in Terminal would show the CPU frequency. On my machine it showed

hw.cpufrequency: 533333332

to reset the CPU back to top speed required a reset of the Power Management Unit (PMU) and a reboot. Now I get

hw.cpufrequency: 866666664

with a VERY noticeable jump in performance - start up time, app loading, file opening etc - it is a REAL performance jump.

The problem is next time I restart (eg after system software upgrade etc), the CPU is reset to 533 MHz. Less than useful.

Another useful command is

sysctl -a

Tried this and

Before PMU reset:

hw.busfrequency: 133121657
hw.busfrequency_min: 133121657
hw.busfrequency_max: 133121657
hw.cpufrequency: 533333332
hw.cpufrequency_min: 533333332
hw.cpufrequency_max: 533333332

after PMU reset:

hw.busfrequency: 133121428
hw.busfrequency_min: 13312142
hw.busfrequency_max: 133121428
hw.cpufrequency: 866666664
hw.cpufrequency_min: 866666664
hw.cpufrequency_max: 866666664

then back to 533333 after restart.

Clearly there is an issue - does anyone have any ideas or similar experiences?

So far, other machines here that we have tried this on also showed lower CPU speeds. How common is this issue?

Would appreciate any other information, experiences - or most importantly - a PERMANENT solution!

cheers and all best, thanks
Eric

[Tomster]

I think the issue has been resolved either here or at www.macosxhints.com Despite what the terminal reports, the cpu actually performs at the speed set by the energy settings preference pane. Benchmark tests are identical. A PMU reset will restore the correct settings, but eventually, it will go back to 533 again.

Run a benchmark and compare results. Of course, ymmv.

[amazing]

There's a good discussion of this issue at macfixit.com. I'm sure you'll find all your answers there...