[pyrite]

is it possible to overclock a Core 2 Duo chip on a mac? i dont know much about PC overclocking other than needing to change bios settings etc.. is this achievable on mac and how? i've heard some ppl have achieved a 40% speed increase on PC!!

[Lateralus]

Nope.

[pyrite]

Originally Posted by Lateralus 

Nope.

dam that sucks

[stefanicotine]

That 40% increase those PC users got wasn't all gain. It seriously shortens the life of your computer and generates an enormous amount of heat. Doing this in a notebook or iMac would be sheer stupidity unless you liquid-cooled it. Even then, your system would lose warranty and become very unstable.

Even if you find a way, I highly recommend avoiding it.

[classof2011]

Sorry, but will someone explain to me what overclocking is?

[Gossamer]

Originally Posted by classof2011 

Sorry, but will someone explain to me what overclocking is?

At its simplest level, you're telling the chip to run at a higher rate than it is set at originally. Some chips run fine at higher speeds, and some do not. It's believed that some chip manufacturers produce an single chip and clock it at different speeds for different price points, so you can buy the cheaper chip and overclock it to the higher speed.
It won't necessarily "seriously" shorten the chips life, but it does have the potential to lower it. The heat produced by a chip increase exponentially with MHz so overclocking a chip from 2.0GHz to 4.0GHz doesn't double the heat output, it squares it. The most serious overclockers go with a liquid cooling system, but often times a good fan system will suffice.
A major factor in life reduction usually comes from increasing the core voltage of the chip so that it doesn't lock up, but this is only usually required if you're going for higher numbers.
Overclocking a fanless device like the mini wouldn't be smart because there's no way to compensate for the additional heat. The notebooks would have a hard time due to small fans, same with the iMac (does it have fans?). A lot more info can be found at Overclocking.net.

[imitchellg5]

iMacs and Mac minis have fans.

[onlyone-jc]

Originally Posted by imitchellg5 

iMacs and Mac minis have fans.

... That aren't designed to dissipate the kind of heat that would be generated from a 40% increase in clock-speed.

onlyone-jc.

[TheoCryst]

Originally Posted by onlyone-jc 

... That aren't designed to dissipate the kind of heat that would be generated from a 40% increase in clock-speed.

onlyone-jc.

True, but they are designed to dissipate (at least on the iMac) up to 2.16 GHz worth of heat. You could probably safely overclock the 1.83 GHz chip in the 17" iMac up to 2.16 GHz without any serious risk. Assuming it were possible on the iMac motherboard which, unfortunately, it is not.

[Gossamer]

Originally Posted by TheoCryst 

True, but they are designed to dissipate (at least on the iMac) up to 2.16 GHz worth of heat. You could probably safely overclock the 1.83 GHz chip in the 17" iMac up to 2.16 GHz without any serious risk. Assuming it were possible on the iMac motherboard which, unfortunately, it is not.

It all depends on the chip. I'd be curious to know if the 1.83 runs at the same temperatures as a 2.16 with similar fan speeds. If so, overclocking would overwork the fans.
(thanks mitchell for the clarification on fans)

[classof2011]

Originally Posted by Gossamer 

At its simplest level, you're telling the chip to run at a higher rate than it is set at originally. Some chips run fine at higher speeds, and some do not. It's believed that some chip manufacturers produce an single chip and clock it at different speeds for different price points, so you can buy the cheaper chip and overclock it to the higher speed.
It won't necessarily "seriously" shorten the chips life, but it does have the potential to lower it. The heat produced by a chip increase exponentially with MHz so overclocking a chip from 2.0GHz to 4.0GHz doesn't double the heat output, it squares it. The most serious overclockers go with a liquid cooling system, but often times a good fan system will suffice.
A major factor in life reduction usually comes from increasing the core voltage of the chip so that it doesn't lock up, but this is only usually required if you're going for higher numbers.
Overclocking a fanless device like the mini wouldn't be smart because there's no way to compensate for the additional heat. The notebooks would have a hard time due to small fans, same with the iMac (does it have fans?). A lot more info can be found at Overclocking.net.

Well if you mean mac mini, I had one and it had some sort of fan inside of it

[Gossamer]

Originally Posted by imitchellg5 

iMacs and Mac minis have fans.

Originally Posted by Gossamer 

(thanks mitchell for the clarification on fans)

Originally Posted by classof2011 

Well if you mean mac mini, I had one and it had some sort of fan inside of it

Got it.

(check the signature guidelines, yours is too big)

[Waragainstsleep]

A CPU can be looked at as a very complicated circuit or collection of circuits. Because it does so many things at once (sometimes in different stages of the circuits or pipeline, sometimes in separate parts), almost all of its work is precisely synchronised by a clock. If the different parts of the chip get out of sync with each other, it will crash. Speeding up the clock will cause all parts of the chip to process their respective tasks faster, but more heat is generated and more strain is put on the microscopic components. Heat increases resistance, other electrical properties can be altered by the increased heat and speed of the system. Current is more likely to 'leak'. All these things will cause the CPU to operate unreliably. Heat is the main cause of problems. If you ever try to run a G4 chip without a heatsink, it will literally burn up. And it won't take long either.

The same models of chip are the same design, but some test better at higher speeds than other. This is what is known as the yield. The manufacturer will get a yield of so many chips per wafer that run at top speed (happy at 2.33 in the case of the C2D), so many will only run 2.16, some 2.0 etc. When a chip is a new design, typically the yield is what controls the overclocking potential of any chip you buy. If a chip has been in production for longer, the process will have been refined all the way along and the yield will be higher. Some faster chips may then end up clocked down to meet orders. These are the ones you hope to get if you want good results at overclocking.

[jdrumstik]

May I mention that OCing the ATI Card works very well seeing as on the MBP CD anyways, Apple under clocked the X1600 to 400/400. Although I only know how to do this in windows with 3rd party apps. But works well for games

[kick52]

try ATIccelerator.