George Zhu’s BLOG

Sometimes, the FSB detection in OS X (especially prior to 10.4.8) could be wrong, you may need to set the correct value manually.To get the correct value, in the Terminal:

$ sysctl hw.busfrequency

this returns the bus frequency, you need to convert it to speed by:

<frequency> / 4000000

After you get the FSB value, open the file:

/Library/Preferences/SystemConfiguration/com.apple.Boot.plist

edit the “Kernel Flags”, and add:

fsb=XXX

to it. Reboot to activate it.