[Peder Rice]

I know, I know; it's way too early to really be discussing this, since (1) we don't yet have the machines, and (2) the machines may not allow overclocking.

However, look at this information about IBM 970 yields:

http://forums.macnn.com/showthread.p...hreadid=169464

Putting this into some percentages, one can find the total percentage of chips that will run at a given clock speed.

1.6GHz.......81%
1.8GHz.......67%
2.0GHz.......28%
2.25GHz......17%
2.5GHz.......5%

So, owners of a low-end PowerMac G5 have a 67% chance of overclocking their PowerMac, at least in terms of yields (sort of, Apple and IBM are probably filtering the chips, but it's interesting data nonetheless).

EDIT: Sorry, accidentally posted before finishing.

[Drakino]

The biggest potential problem that I see with overclocking right now is what that will do to the overall system bus. How much does the CPU regulate this in the new G5 machines? Also, can the chipset used in the 1.6 (the non PCI X one) handle the faster speeds?

The best bet for overclocking will probably be the 1.8 model, to try and go for 2.0 on it.

[HotSoup]

Wouldn't that be dangerous? I mean the G5 already has 9 fans, it's already probably super-hot.

[The Placid Casual]

Originally posted by HotSoup:
Wouldn't that be dangerous? I mean the G5 already has 9 fans, it's already probably super-hot.

I suspect some of those fans will be for the Superdrive and PCI cards... The number of fans in this case [sic!] is not an indication of heat.

Also I think that Apple are using lots of quieter fans rather than 2 or 3 monster decibel ones...

Also, wouldn't the custom asic memory controller chip (that controls bus speeds etc) be a serious problem to overclocking?

Peace,

Marc

[rezzi]

I can see it now....someone's going to post: "had my single proc G5 overclocked to 4 ghz before the entire unit melted into a smoldering hunk of metal and plastic". Probably better not to overclock, but some brave/rich soul is going to try it.

[cdhostage]

Mmmmm, an overclocked G5 2x2GHz model going to 2x4Ghz... You probably would need to run a water cooling system that dumps heat to a constant flow of water. Mmmm... you could spray the inside of the computer very thoroughly with diamond dust, then affix a metal honeycomb structure as long as the computer through all previous air channels, and run cool water past the thing constantly, dumping out the heat to the sewer (or cooking your potatoes!) instead of to the air.

Or better, the SpaceMac G5...

[zeekyhbomb44875]

im into overclocking PCs, and im not exactly a mac fan. only reason i found this site is caus i was lookin for someone else whos modded a G3 powerbook (just got one yesterday). and on the overclockin thing in a mac, i have no idea how the bus speed and multi are controlled in macs,(edit) well of course the clocks are controlled by te PLL, but i dunno if you have to replace refrence crystals, build new oscillators for the system bus freq. or what (/edit) but on the cooling issue, the number of fans could be because of the noise of them, the quieter the fans the less air they move, so therefore requiring more, and the lack of proper heatsinks in the mac. again, im into OCin high heat output athlons. so if you were to start swapping out the stock mac fans with high flow fans (see vantec tornados ) the cooling would be greatly improved, and if there was a better heat sink(s) on the component(s) it would also reduce the temps of what the cpmponents are running at. and also, just replacing the stock thermal compound can make somethin run a bit cooler. and for the guy who touched on water cooling, dumpin ino the sewers? nah... run a closed loop, with a radiator. takes the heat back out of the water and puts it back into the air. you could also run a water chiller for better results. and if you're really creative, build a phase change cooler for the CPU. then to overclock further, volt mod the chipset and CPU. but in doing so you'll increase the heat ouput, requiring more cooling. yeah i am a bit into overclocking in the PC world. if theres any major differences between macs and PCs im missing here, lemme know.