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These new Dual 1.42s must be SCREAMING hot. It's just 340 MHz more than my Dual 1.25 which has an aluminum heat sink. Any insight into this? Is it kind of like Apple's move from Titanium to Aluminum in the new PowerBooks -- more efficient material? Guess so.

Interesting.

Link >>> http://duxbury.la/images/142a.jpg
 

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Strange, I was all set up to be surpised by the size of it, but it looks smaller than the Dual 1Ghz we still have on display. Hrm. Copper must be better at syncing the heat out.

--PB
 

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PosterBoy wrote:
Copper must be better at syncing the heat out.

As RobTheGob pointed out, copper has less than half the thermal resistance of aluminum, and thus is better at dissipating heat.

Since Apple switched to copper for the 1.42GHz, I wonder how big the heatsinks would've been if they had been made out of aluminum (that, and just how much is Apple overclocking these chips).
 

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Overclocking these chips? Giant heat sinks?

Are we intruding into PC territory here? :eek: :eek:

Apple computers are a whole different breed. Thats why we like them so very much.

A giant leap forward for Apple?

Cool...sign me up. :cool: :cool:
 

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Actually, the G4 is no stranger to the G4 case, as Apple has been shipping PowerMacs without processor fans for a while now, and to make up the difference they have been using gi-normous heat syncs with fans blowing across them.

--PB
 

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Aluminum is a pretty effective heatsink material; it has properties that are advantageous over copper. One example is it's easier to create complex and more efficent shapes with al over cu (aluminum can be extruded easier, for instance), it is lighter, and it's heat conductivity is excellent.

Copper, on the other hand, is more effective where a compact sink design is required, negating the drawbacks of higher weight and more difficult shape manufacturing. Both materials have excellent machining properties, but machining is more expensive than extrusion.

My guess is the change to (more expensive) copper is due to the physical size an aluminum one would have had to be for the same effective dissapation; as Al sinks get larger, they become less effective (requiring them to be larger still, etc). Both materials, properly designed, are excellent for the task. The one you select is based on the specific properties required for a given application.
 

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I've seen these aftermarket copper heatsinks before, when I was overclocking my PC's and needing some extra cooling. I came across this heatsink and even seen them modified to have water running through them and to an external fan and radiator :eek:
Yes, water, inside a computer. I wouldn't want a leak. :D
 

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<BLOCKQUOTE>quote:</font><HR>Originally posted by macnutt:
Overclocking these chips? Giant heat sinks?

Are we intruding into PC territory here? :eek: :eek:

<HR></BLOCKQUOTE>

I was overclocking Mac's long before the PC's guys had even heard the term. It may be very poopular (insert Chretien joke here) on the PC platforms now, but I personally think it was far more prevelanet on the Mac stuff 10-12 years ago...
 

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RtG, what exactly is involved in "overclocking"? I have heard various tech persons speaking of this, usually in hushed tones. I realize that it would void a warranty, but is it considered an illegal act?
 

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Dr G, it goes something like this:
Overclocking is taking advantage of a processor/motherboard's ability to run at higher clock speeds (usually, by enabling a higher bus speed or multiple).

It is not "illegal" in any sense of the word, although it does almost always void a warranty for obvious reasons.

Often the steps are as simple as removing, adding or changing a jumper on the motherboard; or swapping in a new oscillator crystal; other times it's a bit more permanent, such as cases where it involves cutting or adding traces on the Printed Circuit Board.

Most overclockers take advantage of the fact that CPUs are often capeable of performing at a higher clockspeed than what they are certified for. There are a number of reasons for this, but generally they can be understood as a way of manufacturers dealing with the real world, where the market meets reality.

If there is a demand for a given chip, companies like Motorola or Intel fill those orders with what's available from the regular production lines. This might take the form of high performance chips rebadged to a lower clock speed, or chips known to be capeable of higher performance only tested at the lower speed (and marked as such).

Since slower chips cost less, they don't really want everyone to know this, but the cat is long out of the bag now.

Chipmaking, being to a large degree a Black Art, there are also occasonal individual units coming off the line that perform much better that its' sister chip of a moment ago. In general, late-production chips are more likely to be good candidates for overclocking than early production; there have been cases that probably are better described as if the chipmaker just doesn't know how anymore to make chips as slow as people are buying.

Some shady manufacturers will use overclock-capeable chips and advertise those speeds rather than the badged speed. Customers end up with more failed hardware (most will work, but not all) and the like.

Not every chip is overclockable; some are good to go at exactly where they are ( and some should be pulled and shoved into a slower computer; but that is a warranty issue).

Since chip manufacturers test for higher performance, these chips cost more, but the rejected chip from a high-speed order may well be a good candidate for overclocking when badged and tested to a lower speed; it depends on what that next speed is.

Overclockers probe those limits by enabling higher bus speeds and seeing what happens next. It's a serious tweak that some people like to do.
 

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gordguide wrote:
Overclockers probe those limits by enabling higher bus speeds and seeing what happens next.

A friend of mine underclocked his PII 266 to 250MHz in order to increase his bus speed from 66MHz to 100MHz. This was back when Intel didn't fix the bus multiplier on their chips, and both 66MHz and 100MHz busses were common.
 

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Thank you, gordguide, for this most indepth description of the process of overclocking. Would this not possibly damage the other components, in that I had thought that all of the components of a computer were integrated in such a manner as to run at a predetermined capacity. It is analogous to somehow putting a "souped up" eight cylinder engine into my wife's VW beetle. If this is a foolish question, don't bother replying. I was just curious about the downside of overclocking.
 

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Now that Dr. G. has been informed of this black art, he must keep his silence forever.

Sorta' like being a Freemason. :D

They are watching and they are watching you !
 

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Macspectrum, take a look on the back of a US $1 bill and check out the pyramid and the "eye". The Freemason's influence is everywhere. I shall not tell.........but "the truth is out there".

Still, I have a hard enough time washing the dishes (I was born a "klutz"), so advanced electronics is not one of my fortes.
 

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Yeah, like gordguide said...

In most cases, it's pretty hard for a manufacturer to determine whether a machine has been overclocked or not. I've had at least two machines in for warranty work after being overclocked. I put the machines back to their pristine shape before taking them in, but in both cases, there had been soldering done on the motherboard.

It's not for people who tend to be nervous, though. I've had some very bad scares over the years, but I'm a hacker at heart. I've been doing mod's for more than 20 years now...

Some mods are scarier than others. These days, most mods are as simple as moving a jumper (B&W G3's), reflashing a card (Radeon 7000!) or setting a menu in the bios (my Abit motherboard)...
 
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