AFAIK, the 750FX needs support for CPU frequency scaling in the  
kernel which we do not yet support, and then a sysctl or userland  
program to activate it. It hasn't really been a priority as we don't  
support power and thermal management to the extent needed for a  
laptop to be allowed to go into high speed mode without damaging the  
computer and/or processor.

On Jul 12, 2005, at 6:35 AM, Francis Koclas wrote:

> I recently gave my trusty old PowerMac 7300 new guts, by buying a 1GHz
> Powerlogix G3 cpu upgrade. That CPU is a 1GHz IBM PPC 750FX, with 1MB
> level2 cache running at 1:1. (got it at OWC)
>
> It did give the 7300 an incredible speed bost (judging by some testing
> I did under Mac OS 9 and Linux)
>
> I managed to get NetBD 2.0.2 running on it (2.0.2 ISO is not bootable
> on OF 1.0.5 machines at the moment). To do that, I had to burn an
> ISO-9660 CD-R with the 2.0.2 install kernel and the ofwboot.xcf file,
> and then boot scsi-int/sd@3:,\OFWBOOT.XCF NETBSD.GZ. That worked fine,
> thankfully. (It's really the only way to go on those machines, boot
> floppies NEVER worked in my experience, and its much easier than doing
> a netboot.)
>
> Noticing the level2 cache wouldn't activate, I came upon posts  
> about L2CR..
>
> I managed to make my own config and put it in my kernel :
> options    L2CR_CONFIG="(L2SIZ_1M|L2CLK_10|L2RAM_PIPELINE_BURST)"
>
> This worked fine, as I now get this :
>
> cpu0 at mainbus0: 750 (Revision 2.3), ID 0 (primary)
> cpu0: HID0 8290c0a4<EMCP,ECLK,DOZE,DPM,ICE,DCE,SGE,BTIC,BHT>
> cpu0: 500.00 MHz, no-parity 1MB WB L2 cache (PB SRAM) at 1:1 ratio
>
> instead of just :
>
> cpu0 at mainbus0: 750 (Revision 2.3), ID 0 (primary)
> cpu0: HID0 8290c0a4<EMCP,ECLK,DOZE,DPM,ICE,DCE,SGE,BTIC,BHT>
> cpu0: 500.00 MHz
>
>
> Now, my question is, how do I make the processor run at its rated 1GHz
> speed, instead of 500mhz? In Mac OS, it defaults to 500mhz, unless I
> use Powerlogix' CPU Director to set it to 1000mhz.
>
> I noticed that when trying linux on it, using BootX, it would get the
> speed set by the CPU Director software. If I booted without the
> extensions, and didn't set the CPU speed, and then boot in linux using
> BootX, i'd get about 994 bogomips. If i let the extensions load
> (therefore loading my 1ghz setting), and then boot linux with BootX,
> I'd get around 1998 bogomips.
>
> A little sorting benchmark showed me that it was really twice as fast
> if I had the correct speed set under mac os prior to loading linux.
>
> So back to my question, is there a way to get my processor running at
> the speed it was made for?
>
> Best Regards,
>
> Francis Koclas
>
>
> !DSPAM:42d39d6284506235120822!
>