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[mcmcjohn]

Hello. The model I have is the Power Mac G4 Gigabit Ethernet. Originally, it had a single-core 1.33GHz CPU, but I wanted to upgrade to a dual CPU. So, I bought a DP 1.0GHz module from a Quicksilver, and I heard that by changing the resistor values, it could be overclocked to 1.2GHz or 1.33GHz. I moved the resistors accordingly to make it 1.33GHz. I also completed the additional 12V power supply modification.

However, after booting, both Mac OS 9 and Mac OS X still recognize it as 1.0GHz. Since this model only has a 100MHz bus, is it normal that changing the resistor like this doesn’t make it show up as 1.33GHz?

[robespierre]

All that the resistors can do is to change the multiplier which the CPU is told to use to configure its internal PLL (clock generator). The OS that is running doesn't "recognize" the CPU speed: software can either perform a CPU benchmark to measure processor performance, or else identify the model and revision of the processor to display the expected clock frequency. In most cases it's the latter, which means that overclocking will not change the displayed frequency.

A program like Newer Technology's Clockometer will try to measure the frequency by testing how many steps of the Decrementer register changes during a second (which comes from the real-time clock, not affected by the processor's clock). It should have a linear relationship to the real CPU speed, but there is some error. Since Apple doesn't want to receive complaints that their 1.0 GHz computer only reports "997 MHz", they don't use this type of measurement in System Profiler.

[aBc]

OR... you might even try:

https://macintoshgarden.org/apps/machspeed-control-combo