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Overclocked G3 MT fan placement

Submitted by john8520 on March 27, 2006 - 5:30pm. PowerPC Macs

Last night I decided to try and over clock my Beige G3 minitower. Well, I was quite sucessful. I brought it from a 366MHz/66MHz to a 455MHz/70MHz, and it runs really fast and stable in OS 9. But I fear that it is getting to hot, so I've decided to put some fans in it.

After a few minutes of rooting around in a parts box, I found two good fans. One is a 12v 60mm fan, the other is a 12v 50mm fan. I would like to attach to the 60mm fan to the big black handle, but there are two spots - one directly above the PCI cards, the other right above the empty space behind the speaker. Im guessing that I should put it over the PCI cards, because my video card gets hot sometimes. Now that I've chosen the placement, do I have it blowing on the PCI cards, or do I have it taking air off the PCI cards?

Now for the 50mm fan. I'd like to attach it to the top of the CPU's heatsink, so I Know that I must remove the springy bit of metal on the powersupply side, which is no problem. But agian I am faced with weather of not I should have it blowing air directly on the heatsink or not. I'm guessing that I should have it taking air of the heatsink, and blowing it to the other fan, which will then take it out of the case.

Any ideas? Thoughts? Comments?

Thanks,

John

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The Czar's picture

Fan Placement

Submitted by The Czar on March 30, 2006 - 7:46pm.

The quick & dirty answer is: It depends. (sorry for the cop out!)

The best approach is to look at the current airflow in the case and see where the air comes in and where the air goes out. Have your fans compliment that airflow.

The *worst* thing you could do is install these fans opposing the current airflow of the tower. That'll result in *less* air cooling.

What I do when I'm trying to figure this out is start the computer up with the case off and just see what way the fans are blowing. Then, I draw a rough diagram and see where the air is flowing, and the direction it's taking. Then, I see where I can attach fans to the case and figure out what direction they should blow.

However, if there's no airflow through the machine at the moment, then you're free to determine the fan placement yourself. Now it depends on what you think is at risk of overheating the most. If you think the CPU is getting too hot for its own good, have the CPU fan suck air off the heatsink and the PCI fan suck that air out of the case. If the PCI cards are getting too hot, reverse the setup. Or, play around with it and see what gets you the best results.

HTH

Cheers,

The Czar

» iBook 14" 1.33Ghz/768MB/60GB/10.4.8
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Well, I decided to clock it b

Submitted by john8520 on April 5, 2006 - 3:55pm.

Well, I decided to clock it back down to 366MHz until I get a thermisitor that I can put in there to check for sure. Thanks for the help!

John

» iMac G5 17" - 160GB HD - 1GB RAM

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