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wr0x2
Sep 5, 2004, 12:00 PM
Use of phase change and liquid nitrogen has been established in the PC world, but even though I've been searching I have yet to find anyone who has done something like this with a mac. Anyone know if someone has ever overclocked a mac cooled with phase change or ln2? (I don't mean TECs, I know that's been done.)

Mord
Sep 5, 2004, 12:04 PM
phase change compressor gear dose not fit in any macs and on one has yet sacrificed a mac to ln2, i may do it some time on a b&w g3 just for the heck of it, just have to get my hands on some liquid nitrogen.

wr0x2
Sep 5, 2004, 12:11 PM
Many people make their own phase change systems, and with a tiny bit of work (no more than needed to make a watercooling adaptor plate) I'm sure this could work. Even something like a vapo or a mach ii could be modded to cool a g3/4/5. I plan on waterchilling (aiming for -30c idle) my beige g3/266 when I get the chiller finished.

FuzzyBallz
Sep 5, 2004, 12:11 PM
Overclocking a Mac? Where is the BIOS? Where are the settings? Why bother?

wr0x2
Sep 5, 2004, 12:14 PM
Overclocking a Mac? Where is the BIOS? Where are the settings? Why bother? I hope that was a joke :rolleyes:.

boxerchip
Sep 5, 2004, 01:59 PM
He may have been joking... but yeah where are those settings?

firewire2001
Sep 5, 2004, 02:17 PM
He may have been joking... but yeah where are those settings?

uhh... they dont exist...

boxerchip
Sep 5, 2004, 02:29 PM
yeah thats what i thought but then that guy was like wtf... is that a joke?

Spock
Sep 5, 2004, 02:32 PM
Apple has jumper setting on the Logicboard.

AppleMatt
Sep 5, 2004, 03:10 PM
There's a on-the-fly ATi overclocking utility being discussed in the gaming forum.

AppleMatt

Mord
Sep 5, 2004, 04:06 PM
all my macs are overclocked :D ibook is at 750MHz from 600 and my cube is at 550MHz from 500MHz.

Numbski
Sep 6, 2004, 11:22 AM
Uh...guys.

Where the heck have you been living the last year? lbodnar, myself, and several others have been overclocking iMacs and eMacs with great results, especially the 800mHz late revision eMacs.

http://www.numbski.net/journal/imac_hack

I've been working on the 800mHz iMac, and I'm quite possibly looking to sell that and go to the new G5 iMac, and even started looking at overclocking that.

In a nutshell, what you need in order to overclock the cpu is to identify the clock chip. Once you've identified it, find a pdf doc on it if available, or call the manufacturer and get them to send you a spec sheet.

Once you have that, you need to identify the pins that control the FSB (Front-Side Bus speed) and the multipliers.

For example, by default my iMac run at 800mhz, which is a setting of 100mHz FSB, with the multiplier set at 8x. However, since from Apple my system came with RAM that ran at 133mHz, it was a pretty safe bet that the system was capable of running at that speed as well.

Anywho, if you look at my site, you'll see that lbodnar has already identified what looks like the resistor bank for controlling the FSB and Multiplier on the G5 iMac from the marketing images. The actual clock chip is obscured, so we can only speculate as to what the settings really are.

Sun Baked
Sep 6, 2004, 02:45 PM
Uh...guys.

I've been working on the 800mHz iMac, and I'm quite possibly looking to sell that and go to the new G5 iMac, and even started looking at overclocking that.Good luck with that, since I don't think I've seen anyone with a definitive G5 overclock page yet.