On Tue, Jan 18, 2005 at 01:59:27PM -0500, Tim Kelly wrote:
> Let me rephrase. At the time of the thread, the procedure may have changed
> the reported value in OF. Currently the approach should not alter the
> reported speed, as it does not retrieve the values from OF.

Sure.  At that time, though, I think it did.

> However, it may
> still be possible to use OF to spend the CPU up to its normal operating
> speed, as it some point Apple must speed the CPU up without putting it to
> sleep during the booting process.

I don't think so on the 7450.  The 7447A (and MPC7448 and perhaps
others) have a "Dynamic Frequency Switching" feature, but I've not
used that.  The newer powerbook sounds like that if it's 1.3GHz
vs. 667MHz.

See sections "10.2.3.3 Deep Sleep Mode" and "10.2.5 Dynamic Frequency
Switching (DFS) in the MPC7447A" in the MPC7450 User's Manual
revision 4.2.

The change on a 7450 doesn't have to be visible.  The CPU just has
to stop, get PLL reconfigured and restart, allowing the PLL to
relock.  I'm not quick enough to see a 667MHz CPU do that...  :-)

-allen

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