Overclocking Sawtooth G4

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Level 1

10 points

Overclocking Sawtooth G4

I have a 500 MHz Sawtooth G4, and I'm considering overclocking it. I'm familiar with the procedure, however does anyone have any experience doing it? I would like to attain at least 600 MHz, ideally 700 MHz, but I am worried about cooling. Does anyone know:

1. What is the normal operating temp for a 500 MHz Sawtooth G4 when at full operation?

2. How high can the operating temp safely go for that processor?

3. Is there any way to measure the operating temp?

4. If the temp were to get too high, would the machine just crash or would I fry and permanently damange my processor?

5. Alternatively, is there is borderline temperature between having the machine just crash and doing permanent damange to the processor?

6. Is there a chance that if the processor got borderline hot that the machine wouldn't crash but just slow down?

Thanks for the help!

G4 (AGP Graphics), Mac OS X (10.4.9)

Posted on Aug 11, 2007 9:16 PM

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Answer 1

japamac

Level 7

24,400 points

Aug 11, 2007 9:48 PM in response to Sawtooth501

Hi-

A hottly debated subject, yours is.

You will find the following articles of interest:

http://www.xlr8yourmac.com/G4ZONE/sawtooth/SawtoothCPUdesign.html
http://forums.macosxhints.com/archive/index.php/t-54582.html

To accurately measure the temperatures of your CPU, you may need a sensor. This is discussed in the following:

http://www.bresink.de/osx/0TemperatureMonitor/issues.html

http://www.applelinks.com/articles/2003/06/20030620104545.shtml

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Answer 2

Aug 12, 2007 9:58 AM in response to Sawtooth501

Hi

I wish you luck but I'd be surprised if you managed to achieve 600MHz. You may already know but the introduction of the 500MHz Sawtooth was actually delayed by a number of months because Motorola were having yield problems and were initially unable to produce enough processors even capable of running at 500MHz. As far as I'm aware the highest frequency Apple ever used was 533MHz in the Digital Audio G4. The higher clocked processors in the 667MHz and 733MHz DA models were a different G4 variant entirely, sometimes known as the G4e, which incorporated a longer pipeline etc so higher clock speeds could be achieved. Both seem to suggest there's limited room to play with in terms of overclocking the processor in the original Sawtooth models.

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Answer 3

Sawtooth501 Author

Level 1

10 points

Aug 12, 2007 11:40 AM in response to Rodney Culling

Well for now I did as it said in the xlr8 your mac article, and overclocked my bus to 133 MHz. This also boosted my processor to 533 Mhz. Been running at max performance for 6 hours straight, no problems at all. Computer is slightly faster. Funny thing too is I have 1.25 GB of RAM of PC100 RAM, and the chips are from different manufacturers. I also have 4 hard drives and an ATA PCI card, and even with all this everything works without a hitch. I did notice after I opened my computer up the heat sink was slightly warmer than it ussually is, but only slightly. The only heat sensor I have in my comp is on one of my hard drives, and prior it was reading 38 C, now it's 39 C, which is completely acceptable. The beautiful thing too is that the system bus required no soldering, only modding the nvram. My biggest concern with actually overclocking the processor is soldering skills - if you've actually looked at what you have to do on the G4 daughterboard both my and my dad deemed that it's way beyond our soldering skills - but I'll still be looking for someone who can do it.

Message was edited by: Sawtooth501

Message was edited by: Sawtooth501

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