I just software overclocked my Rev A. G4 400 to 533MHz!
Well, sort of. Following instructions on XLR8yourmac.com I went into the Open Firmware prompt and typed in a few commands to increase my system bus from 100MHz to 133Mhz.
Suddenly on restarting my G4 it happily proclaims to be a G4 533MHz in About this Mac and Apple System Profiler (10.2.5).
I was in a state of shock at first - over 25%. The XLR8yourmac article stated that it probably wont work over 50MHz but I have been running it at that speed for a few weeks now with less than 1º increase in heat.
Has anyone got any comments/suggestions (apart from EVACUATE!).
For those interested - these are the commands I typed (from xlr8):
"How to edit and store the NVRAMRC for 133MHz bus
(1) Boot by holding down "Cmd" + "Opt" + "O" + "F" keys to enter the OpenFirmware terminal.
(2) Enter the NVRAMRC editor. (<return> shows you should type "return" key)
nvedit <return>
(3) Type following script exactly (including spaces).
" /" select-dev <return>
7efdc44 " clock-frequency" get-my-property 2drop ! <return>
" /cpus/PowerPC,G4@0" select-dev <return>
1fca0554 " clock-frequency" get-my-property 2drop ! <return>
7efdc44 " bus-frequency" get-my-property 2drop ! <return>
1fbf711 " timebase-frequency" get-my-property 2drop !
(4) Type "Cntl" + "C" to exit NVRAMRC editor.
(5) Save the script
nvstore <return>
(6) To enable the NVRAMRC, type this command.
setenv use-nvramrc? true <return>
(7) Reboot with new timebase constant.
reset-all <return>
"
Well, sort of. Following instructions on XLR8yourmac.com I went into the Open Firmware prompt and typed in a few commands to increase my system bus from 100MHz to 133Mhz.
Suddenly on restarting my G4 it happily proclaims to be a G4 533MHz in About this Mac and Apple System Profiler (10.2.5).
I was in a state of shock at first - over 25%. The XLR8yourmac article stated that it probably wont work over 50MHz but I have been running it at that speed for a few weeks now with less than 1º increase in heat.
Has anyone got any comments/suggestions (apart from EVACUATE!).
For those interested - these are the commands I typed (from xlr8):
"How to edit and store the NVRAMRC for 133MHz bus
(1) Boot by holding down "Cmd" + "Opt" + "O" + "F" keys to enter the OpenFirmware terminal.
(2) Enter the NVRAMRC editor. (<return> shows you should type "return" key)
nvedit <return>
(3) Type following script exactly (including spaces).
" /" select-dev <return>
7efdc44 " clock-frequency" get-my-property 2drop ! <return>
" /cpus/PowerPC,G4@0" select-dev <return>
1fca0554 " clock-frequency" get-my-property 2drop ! <return>
7efdc44 " bus-frequency" get-my-property 2drop ! <return>
1fbf711 " timebase-frequency" get-my-property 2drop !
(4) Type "Cntl" + "C" to exit NVRAMRC editor.
(5) Save the script
nvstore <return>
(6) To enable the NVRAMRC, type this command.
setenv use-nvramrc? true <return>
(7) Reboot with new timebase constant.
reset-all <return>
"