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Why not Water cooling? - Page 2  

post #41 of 220
Thread Starter 
Quote:
Because let's face it, if Joe Blow tries to modify his cooling system and anything went wrong, you'll have liquid all over the internals of your computer, obviously laying waste to any warranty the owner may have possessed. And with customizable cooling configurations, the person making said customizations would need to things about thermal dynamics and other such areas of education that most people are not privied to. Just saying "this area is hotter so I'll run more pipe to it" is not an acceptable idea.

What if it had an internal fan so if you did add something to it the fan could then be used in addition to the water cooling system? It wouldn't be silent anymore but it would still be less noisy than the alternative.

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Did I say that?

No, you didn't. That is why I asked.

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Eventually, I'm certain this will happen.

What will allow it to happen?

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But I guarantee you no such technology will be available in a form that the average or even above average end consumer can arbitrarily reconfigure. This is very complex technology and not meant to be played with.

- See my first answer in this post.

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I'm trying to think of an example of expensive consumer products that are liquid cooled and allow the consumer to customize the cooling configuration. I'm not saying there aren't any, but I can't come up with one. Does anyone else know of any?

Just because it hasn't happend yet doesn't mean it is impossible.

Also, the pee cees that are liquid cooled can be modified. You just have to follow the instructions to do it.

You could also pay your Apple dealer to do it like you have things done to your car. Considering that the ultimate G5 from the apple store costs more than some cars this doesn't seem entirely bizarre.

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I'd also like to add that the hotter you make a machine run through upgrades, the faster you'll need to cool the liquid running through this machine. These systems are designed to cool the liquid down to a predetermined temperature in a predetermined amount of time. Once the machine becomes hotter, the liquid isn't cooled fast enough, and you have unstoppable heat buildup. Now you are asking the user to manually adjust the cooling rate and/or distribution of the coolant itself, and that's something virtually nobaody is qualified to do.

You just need a thermostat and a radiator large enough to handle a higher capacity than the stock system. Autos have been doing this for a hundred years.
post #42 of 220
Quote:
Originally posted by iSegway
What will allow it to happen? ... Just because it hasn't happend yet doesn't mean it is impossible.

What will allow this to happen is better technology. And I agree with the second point, as I'm certain as computers continue to run hotter, liquid cooling will become a necessity. At some point no amount air fan-circulated air will cool these machines.
Common sense is the collection of prejudices acquired by age eighteen. - Albert Einstein

I wish developing great products was as easy as writing a check. If that were the case, then Microsoft would...
Common sense is the collection of prejudices acquired by age eighteen. - Albert Einstein

I wish developing great products was as easy as writing a check. If that were the case, then Microsoft would...
post #43 of 220
Thread Starter 
Quote:
What will allow this to happen is better technology.

This is what I am saying though. In my opinion all the technology is there and it was sorely needed in the G5. Why wasn't it used?

Price is a possibilty... but these components are not expensive. The G5 case is made entirely of aluminum which could have been used as a radiator. Either making the G'5 half the size or allowing massive expandability.

As you say, this technolgy is going to have to come sooner or later. The G5 needs it now. Why not start investing in the future?

Lord knows they had plenty of time to engineer it while waiting for the 970.
post #44 of 220
Quote:
Originally posted by iSegway
You just need a thermostat and a radiator large enough to handle a higher capacity than the stock system. Autos have been doing this for a hundred years.

as for this comment, you also need to realize that the very automobiles you mention have massive amounts of air rushing over these radiators as you drive. And radiators on autos stay very hot for long periods of time, and people want to get in and work on their compters when they want to. They don't want to have to wait for the radiator to cool off.

And the cooling system inside an automobile is so complex that few people can do any work on them. However, far more computer owners know how to perform upgrades to their computers. Once you start making these things overly complex, the average user will no longer be able to maintain their product. Just like cars. 30 years ago everyone was under the hood working on their vehicles. Now with eveything that has been added onto them, it's incredibly more difficult.

I'd hate to have to take my computer to the Apple store to have my cooling system reconfigured every time I made a modification to it.
Common sense is the collection of prejudices acquired by age eighteen. - Albert Einstein

I wish developing great products was as easy as writing a check. If that were the case, then Microsoft would...
Common sense is the collection of prejudices acquired by age eighteen. - Albert Einstein

I wish developing great products was as easy as writing a check. If that were the case, then Microsoft would...
post #45 of 220
Thread Starter 
Quote:
as for this comment, you also need to realize that the very automobiles you mention have massive amounts of air rushing over these radiators as you drive. And radiators on autos stay very hot for long periods of time, and people want to get in and work on their compters when they want to. They don't want to have to wait for the radiator to cool off.

This sytem would run no where near the temperature of an automobile. You wouldnt have to wait one second to work on your computer.

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And the cooling system inside an automobile is so complex that few people can do any work on them. However, far more computer owners know how to perform upgrades to their computers.

The cooling system on a computer would be no where near as complex, and cooling systems on cars are not that complex now. Probably the least changed system in the history of the automobile.

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Once you start making these things overly complex, the average user will no longer be able to maintain their product.

How do you know it would need to be overly complex for the user? Or how would it be overly complex?

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Just like cars. 30 years ago everyone was under the hood working on their vehicles. Now with eveything that has been added onto them, it's incredibly more difficult.

Computers will get to this point, as well. Just a matter of *when*. Are you saying you would rather have one of those old cars?

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I'd hate to have to take my computer to the Apple store to have my cooling system reconfigured every time I made a modification to it.

I mentioned an alternative before. All you would have to do is turn on a fan that was already built into the case or that was activated by the thermostat.

Why wouldn't this work?
post #46 of 220
Quote:
Originally posted by iSegway
This sytem would run no where near the temperature of an automobile. You wouldnt have to wait one second to work on your computer.

And you know this how? I mean the system is hot enough now that it needs 4 thermal zones and 9 fans. Placing all that heat into one centralized area (the radiator) would focus the heat thus making this area of the computer hotter than computers with larger cool zones as they are now.


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The cooling system on a computer would be no where near as complex, and cooling systems on cars are not that complex now. Probably the least changed system in the history of the automobile.

And despite the fact that the cooling system is largely unchanged, few people are qualified to work on it. Why? Because it is such an integral part of the system that auto manufacturers don't want hobbyists toying around with them. The risk far outweighs any perceived reward.


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How do you know it would need to be overly complex for the user? Or how would it be overly complex?

If it were child's play to implement this technology, it'd already be there. That in itself is proof enough. As for the end user, again, I'm unaware of liquid cooled products that are able to be reconfigured at will by the end user with minimal knowledge. Therefor to me it implies this isn't as easy to do as some would assume it to be. (ie it's complex)


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Computers will get to this point, as well. Just a matter of *when*. Are you saying you would rather have one of those old cars?

As someone who enjoys working on cars, yes I much prefer working with older vehicles in which one is much more capable to do the work. And with all the bullshit that has been loaded onto cars, do they actually get you where you're going any faster? Virtually all major advancements in the automobile in the last 50 years have centered around 2 things: comfort and safety. Safety is really not applicable here, so let's look at comfort.
Comfort for an autombile driver/passenger is having everything at the puch of a button and as little interaction with the automobile as necessary to be completely happy with the vehicle experience.
To an extent, this rings true with computer consumers as well. but there is a far greater percentage of people using computers that want the ability to get into the guts of their machines to tinker than there is for the automobile consumer. Thus you need to keep the internals of the machine as simple as possible for the end user to reconfigure, something that the automobile industry really doesn't take into consideration.
I'd rather liken computers to things like Harley's rather than cars. Harleys are complex but also designed to be completely customized, whereas the automobile is complex and it's a pain in the ass for the average person to upgrade major components of them.


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I mentioned an alternative before. All you would have to do is turn a on fan that was already built into the case and that was thermostatically activated.

Why wouldn't this work?

But turning on a fan, although a plausible idea, is basically doing it ass backwards, because the entire point of liquid cooling is to eliminate the dependency on a noisy fan. If getting rid of the fan is the idea, then get rid of it. Don't take 2 steps forward and 1 1/2 back.
Common sense is the collection of prejudices acquired by age eighteen. - Albert Einstein

I wish developing great products was as easy as writing a check. If that were the case, then Microsoft would...
Common sense is the collection of prejudices acquired by age eighteen. - Albert Einstein

I wish developing great products was as easy as writing a check. If that were the case, then Microsoft would...
post #47 of 220
Thread Starter 
Quote:
And you know this how? I mean the system is hot enough now that it needs 4 thermal zones and 9 fans. Placing all that heat into one centralized area (the radiator) would focus the heat thus making this area of the computer hotter than computers with larger cool zones as they are now.

Yes and put your hand on the stream of air it won't even feel warm. In a liquid cooled computer the temperatures would be even less. What makes *you* think it would be *hot* to the touch? Because a cars coolign system is?

The G5 has 9 fans and all those cooling zones because they are trying to reduce the noise of the fans and keep it cool too. Which is impractical with air cooling. And quite easy with liquid cooling.


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And despite the fact that the cooling system is largely unchanged, few people are qualified to work on it.

I work on the cooling system of my vehicle all the time. Don't you? Unless your vehicle is covered by a warranty you could too. A warranty doesn't mean it is complex... just that they aren't going to pay for your screw ups.

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Why? Because it is such an integral part of the system that auto manufacturers don't want hobbyists toying around with them. The risk far outweighs any perceived reward.

Manufacturers don't want hobbyists toying with anything in cars now. That doesn't mean that it is too difficult to do. That is just a by product of our litigious society. Now *that* is apples and oranges!

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If it were child's play to implement this technology, it'd already be there.

Does it have to be child's play? I don't think anything about the G5's engineering would be considered child's play.

I just showed you a lpatop that uses this technology and is tiny and can be touched with the naked hand and actually prevents hot spots on the case as I mentioned earlier about the cooling system not getting hot.

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That in itself is proof enough. As for the end user, again, I'm unaware of liquid cooled products that are able to be reconfigured at will by the end user with minimal knowledge. Therefor to me it implies this isn't as easy to do as some would assume it to be. (ie it's complex)

Because something hasn't been done it isn't proof that it can't be done. It just means that no one has done it yet. But someone will... oh wait someone already has. And they did it in a laptop which is more difficult because you have to carry it around and keep the weight down and prevent leaks even though it has to deal with beiang dropped and shaken constantly.

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As someone who enjoys working on cars, yes I much prefer working with older vehicles in which one is much more capable to do the work. And with all the bullshit that has been loaded onto cars, do they actually get you where you're going any faster?

probably faster, yes. And quieter, and more efficiently and cheaper considering the weight of vehicles has decreased and cars last a lot longer than they did, especially for the price of materials. And they handle much better. There has been a ton of progress.

[quote]Virtually all major advancements in the automobile in the last 50 years have centered around 2 things: comfort and safety. Safety is really not applicable here, so let's look at comfort.[quote]

this is just wrong. There has been huge progress made on all levels.

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I'd rather liken computers to things like Harley's rather than cars. Harleys are complex but also designed to be completely customized, whereas the automobile is complex and it's a pain in the ass for the average person to upgrade major components of them.

Harleys cost a fortune. Harleys have changed very little technologically over the years and are *extremely* expensive and don't hadnle well. Are heavy as heck.


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But turning on a fan, although a plausible idea, is basically doing it ass backwards, because the entire point of liquid cooling is to eliminate the dependency on a noisy fan. If getting rid of the fan is the idea, then get rid of it. Don't take 2 steps forward and 1 1/2 back.

I don't even think you would need to turn on a fan. What are you going to be adding to it? Supposedly you can't change the G5 processor anyway(this time out at least) You rarely change a processor anyway, I don't think it would be so bad to have your retailer do that service.

What makes you think one fan to remove a small amount of extra case heat would be that noisy? You are claiming that 9 fans aren't noisy... how could one fan venting the case be that noisy? The water cooling system is handling the major load anyway.

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If getting rid of the fan is the idea, then get rid of it. Don't take 2 steps forward and 1 1/2 back.

This isn't the only point. You need to go back and reread my reasons for doing this.
post #48 of 220
ok, we agree to disagree. I'm not going to give myself carpal tunnel discussing the cooling system of the G5.
Common sense is the collection of prejudices acquired by age eighteen. - Albert Einstein

I wish developing great products was as easy as writing a check. If that were the case, then Microsoft would...
Common sense is the collection of prejudices acquired by age eighteen. - Albert Einstein

I wish developing great products was as easy as writing a check. If that were the case, then Microsoft would...
post #49 of 220
I've lost track. Why do we need a water cooled system?
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post #50 of 220
Thread Starter 
Quote:
Originally posted by bunge
I've lost track. Why do we need a water cooled system?

Don't you know why you need water cooling?

Or was that comment just spam?

I know why I need it.
post #51 of 220
Quote:
Originally posted by iSegway
Don't you know why you need water cooling?

Or was that comment just spam?

I know why I need it.

The G5 is supposed to be quiet. If it's as cool as water, as quiet as water, and cheeper than a water system, why do we need water cooling?
"Hearing a corrupt CEO like Cheney denigrate Edwards for being a trial lawyer is like hearing a child molester complain how Larry Flint is a pervert." -johnq
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post #52 of 220
Thread Starter 
Quote:
The G5 is supposed to be quiet. If it's as cool as water, as quiet as water, and cheeper than a water system, why do we need water cooling?

Because it is as complex as water cooling , noisier than water cooling, much bigger than water cooling, dirtier than water cooling, and ugly compared to water cooling, don't forget ridiculous. Not to mention a waste of time, because unless there is some revolutionary new cooling system developed Apple will end up going to that in the very near future anyway.

BTW, how do you know that the fan system is as cool, as quiet and cheaper than water cooling?
post #53 of 220
There are a variety of cooling systems. As far as personal computers are concerned there are all effectively air cooled systems as you have a hot CPU on one end and warm air on the other end.

The simplest method is a heat sink, basically a piece of metal that contacts the CPU. Heat flows out from the CPU to the extremities of the heat sink and is transferred to the air. Heat sinks' fault is that they rely on the ability of the metal in the heat sink to conduct heat.

Systems which rely on fans, pumped liquids an heat pipes all assist the transfer of heat from the CPU to the air because the moving material carries heat faster than heat flows throw a stationary piece of material.

Refrigerators use some sort of active device to pump heat out of the heat source. There are a huge variety of these. Joule-Thompson, Peltier, Sterling and other effects are all employed in active coolers. Conceptually, my favorite is Anti-Stokes cooling. In this method a powerful laser shines on a special material which is cooled by the laser.

All of these methods can be modeled in excrutiating detail. Engineers can compare cooling power, cost, efficiency, weight, etc. to more than adequate precision. Reliability can be estimated but reliability is very hard to deal with in a complex system with moving parts.

When it works, a heat sink with a fan is hard to beat. Not much is cheaper or more reliable than a piece of aluminum that just sits there. I enjoy all the discussions about different possible ways to cool computers.

I did a very short, unscientific search for liquid cooler kits for Pentiums. They run $150 to $200 as kits, you supply your own labor. It seems this would add $200 to $500 to the price of a computer. That is why most computers ship with heat sinks and fans, apart from the reliability issue.
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post #54 of 220
Thread Starter 
Quote:
reliability is very hard to deal with in a complex system with moving parts.

My favorite method would be a stirling engine. I don't expect apple to have gotten that in the G5 though. Even though Jobs is friends with one of the premiere stirling developers in the world.

Water cooled though? What moving parts? The water pump? 44 thousand hours for the laptop one in this thread.

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When it works, a heat sink with a fan is hard to beat. Not much is cheaper or more reliable than a piece of aluminum that just sits there. I enjoy all the discussions about different possible ways to cool computers.

Heatsinks are too inefficient - hence noisy - with only a fan system. That is why the G5 is as big as it is, and still not silent.

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I did a very short, unscientific search for liquid cooler kits for Pentiums. They run $150 to $200 as kits, you supply your own labor. It seems this would add $200 to $500 to the price of a computer. That is why most computers ship with heat sinks and fans, apart from the reliability issue.

uh... shouldn't the systems be cheaper with mass production and much larger volumes being sold? Not to mention reduced material costs because of a smaller enclosure?

I mean people act as if this is the most expensive thing in the world. Aluminum piping? Probably less material cost than the heat sinks. The casing is all aluminum on the G5 anyway. Turn that into a radiator. Where as the case of the G5 now is huge. It has 9 fans. 4 of them are immense. At least four large aluminum heat sinks and 2 of those are huge. The water cooling system needs a tiny pump and a thermostat. I think the G5 has a thermostat now anyway. So where are these massive costs?
post #55 of 220
Quote:
Originally posted by iSegway
No you wouldn't. This is absolutely wrong.

It's absolutely right. It's the way all water cooling works, in all implementations (well, OK, except for your seaside nuclear reactors). The water moves the heat to a radiator, which is air cooled.

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And perhaps it isn't. Considering that many people use it on desktops. Overclock with it. And it is still near silent.]

How loud were the systems beforehand, and how efficient was their air cooling? Were they carefully partitioned and controlled like the G5, or were they the haphazard tangle of devices and cables inefficiently cooled by randomly placed fans, like the average OCer's ATX box?

In other words, quiet relative to what? The G5's fans run at 1/10th speed by default, and they're large, which cuts down both real noise and perceived noise (because psychologically, low notes are less intrusive than high notes at the same decibel rating). I'd be amazed if you could hear that at all. The fans would only become loud under exceptional circumstances, and in that case I think most people would prefer a roar to, say, their computer melting.

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And how do you know this? And even if it did: So? Maybe a *good* water cooled system would last longer than a good fan.

I'm going by the numbers claimed by Hitachi, vs. the fan-cooled PowerBook that served my mother flawlessly for 10 years (it still runs, but batteries have gotten prohibitively expensive).

The basic question you have to answer is, if it is so incredibly, blindingly obvious that liquid cooling is superior in every aspect, then how come the overwhelming majority of computers still use fans? Even the liquid cooling in cars is worthless without seriously loud fans, or the equivalent (moving the radiator rapidly through the air). And I'd bet that CPUs have a much higher heat density than any part of an engine block. The P4 was heading for the heat density of a reactor core. That's when you want something that can draw heat off the CPU and dissipate it as efficiently as is practicable. Water's pretty slow about that. The liquids that do it efficiently, like liquid sodium, are hair-raising.

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How much would the price mark-up be?

That's an implementation issue. How hard is it to put in a water-cooling system that can channel away the heat of two small, near-100W CPUs (for starters) and maintain the reliability, ruggedness and ease of egress that characterize the PowerMac now? How do you keep the pump and whatever cools the radiator below the current PowerMac's 35dB? Airflow is free and you don't have to worry about getting it on your components. Fans - even good fans - run pretty cheap. And given the hardware you're getting, the price premium on that Hitachi is pretty outrageous. $3000 for 20GB and 128MB of RAM?! Here's a project for you: Find a similarly configured fan-cooled notebook and price it. There's your premium.
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post #56 of 220
Quote:
Originally posted by iSegway
Because it is as complex as water cooling , noisier than water cooling, much bigger than water cooling, dirtier than water cooling, and ugly compared to water cooling, don't forget ridiculous. Not to mention a waste of time, because unless there is some revolutionary new cooling system developed Apple will end up going to that in the very near future anyway.

As far as I can tell, the only argument you have is that fans are dirty.

As for the revolutionary new cooling system developed by Apple, it's actually being developed by IBM. It's the next generation 970 chips that run cooler than the current generation. As I already said, the next generation of machines using this case might be cooler because of a cooler chip. If so, it would not make sense to invest in a water cooled system for just one iteration of this case.
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post #57 of 220
Thread Starter 
I guess we will just have to agree to disagree on this one, as rageous said. If you or anyone else really would like to see the case for the G5 improved dramatically I suggest doing a lot more research into water cooled personal computers. In my reseach your concerns for this type of system are unwarranted.

I would like to thank you guys for your participaction in this thread, though. Your opinions on this matter have been very helpful to me.
post #58 of 220
I've enjoyed reading the forum posts (very lively!), and I though I'd chime in.

Would there be a real risk of damage/rapid deteriation of computer components if set over shallow water in a pan of smooth rocks? I mean elevated by a few inches and with good air movement. This works incredibly well (evaporative cooling), and it just seems that this process could be utilized with some forced air (upward) through the case bottom. Would this mean a lot of rust in a hurry?
post #59 of 220
Apple will not add a liquid cooling system to their systems anytime soon. It interferes with the whole "simplicity," easier and faster image which the Macintosh holds. Nobody, who is merely interested in having a speedy computer to use for work, will want to get their G5, plug in the power cable, ADC cable, Mouse and keyboard (unless they go wireless as I think they may very soon), and then of course open up the computer and pour a specific amount of water into a container and then add another liquid component from some additional bottle, etc. . . the whole idea is bothersome, clumsy.
Added to this is the already mentioned factor of leaks. Most who have liquid cooling systems opt for a window on the side allowing them to get a quick peek at the insides and check if everything is as dry as it should be.

Systems do now come configured with liquid cooling by default. A great example would be VoodooPC (the ferrarri of all pc manufacturers), which has a patent pending liquid cooling system shipping, or soon to be shipping with their F-510 Stealth systems. The system cools both the CPU and GPU, along with its RAM.

One should also consider thermal electric cooling, as in the SubZero4G system from Thermaltake. It's a lot less bothersome.

As far as I see it, the fan set up makes the most sense at the moment. I do wonder though why apple didn't opt for a front intake fan, of course that would increase the noise level a bit.
post #60 of 220
I'm not trying to come down on either side of this argument so lets see if I can more light than _heat_ to this discussion. 8)

Imagine that a single P4 using 100W (arbitrary) did not have any cooling except the air flowing around the chip. It would be the same as a 100W light bulb and the chip would reach several thousand degrees Kelvin as it destroyed itself.

You need to extract as fast as it is generated in order to keep the temperature down.

There are only two ways to cool something down. 1) Heat is transferred from a warm object to a cooler object when they are in contact. 2) Heat radiation (IR) is transmitted from a warmer object to a cooler object. In the case of cooling CPUs the second effect doesn't come into play. Somehow, the heat generating CPU has to be in contact with something cooler (heat sink, air, water, Peltier cooler, etc.) than itself.

The first problem is to get the heat from the chip to the package. This is an important part of the design. Special materials and packaging are designed to let the heat escape from the chip itself to the package. If the chip carrier were made of some kind of insulator then no matter what sort of heat sinks or liquid cooling were employed the chip would self destruct.

So now we have to cool the case of the chip which is being fed 100W internally. If you want to cool this with air you can estimate that you want to have the air increase by perhaps 10 degrees centigrade. You can now calculate what mass of air has to be pushed over that surface each second to carry away 100W with the specified change in air temperature. I'll leave it as an exercise for the reader but it will be a lot of air and to have it pass over that small surface it will be going very, very fast.

Now let's add a heat sink. The same amount of heat has to be dissipated but now it will be spread over a much larger area. The heat sink restricts the heat flow to some extent so the chip temperature will be a little higher. The engineer working on this has to consider this when designing the heat sink. Depending on the specifics you might need a fan or simple convection (as in the G4 Cube) might be adequate. With 100W you will probably need a fan.

Now let's use a liquid cooler. The situation is basically the same. You now have water passing over the same small chip package and it has to carrry away the same amount of heat. You can do the calculations to figure out how fast the liquid must be pumped in order to keep the chip temperature within specifications. Liquids are much more dense than air and so the liquid can be pumped more slowly and with less noise than air to keep the temperature down.

This simply changes the problem from how to get heat out of the chip to how to get heat out of the pumped liquid. There is nowhere else for the heat to go but to the air. In a closed loop system this is done with a radiator. Basically, this is a metal heat sink in contact with the air. The advantage is that the radiator can be quite large and the larger the heat sink the slower the air in contact with it has to move. Depending on the size of the heat sink you could rely on convection (like the G4 Cube) or you could use a fan. Because the liquid is pumped the designer has a lot of latitude in choosing the size of the radiator. There is no magic to liquid cooling. The same amount of heat has to be dissipated. You just have the option of dissipating it remotely and over a larger surface area.

In the case of the Hitachi laptop it seems that they are putting the radiator in the lid. It is not clear if they are using a fan or relying on convection. It seems as if they are relying on convection.

In the case of a tower putting out 100W+ you would need a prohibitively large heat sink in order to rely on convection.

The earth receives a little over 100W per square meter from the sun. Think how a piece of black plastic in full sun becomes. That black piece of plastic is passing that energy to the air.

The alternative is to use a smaller, more practical, radiator and cool that with a fan. If there is too much heat to do this then you can add an active chiller (a refrigerator) to the radiator. It will pump heat into the radiator sending cool water to the CPU. This adds cost and complexity and now you have to remove even more heat. With a large enough radiator using enough sound insulation this could probably be made to run quietly.

My opinion is that you could quietly cool a G5 with either a liquid cooler or with a heat sink and a fan. There would be differences in cost and reliability.

As the power used by the chip increases, as some forecast for the future, the heat sink may not be able to conduct heat away from the chip fast enough to keep the chip temperature within specs. In this case some sort of active cooling (liquid or other) would be required. I don't know quantitatively when that would happen.

One personal note, I've had a fair amount of experience with liquid cooling, radiators, chillers and such. They all work well for short periods of time. It is amazingly difficult to have these work reliably year after year. Hitachi has excellent engineers. Hitachi has a wealth of experience in working out the painful little details of making a small, reliable, quiet closed loop recirculator as they put in their laptop. I am sure it will work well. Also, knowing Hitachi, I can't imagine it is cheap.
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post #61 of 220
Quote:
Originally posted by iSegway
[B... lacks expandability because it needs all this room for air flow.

- ugly perforated panels for ventilation

- still noisy!

[/B]

It is expandable, 8 gigs of memory 500 gigs of storage and 3 pci-x slots plus all the firewire and usb ports, oh and the optical digital audio, just how much crap do you need to shove into your computer?

Ugly is just an opinion, I like the way it looks.

How do you know its still noisy? Did you buy one off ebay

Your dust worries? I have a 17" iMac sitting here and I have no idea how to open this thing up to clean it out, at least with the G5 it has this nice big door that gives you access to everything so you can easily blow it out. And well if you still have dust problems then maybe you should clean your place up some and bathe more regularly (most house dust is human skin)

Liquid cooled systems will show up one day, prolly sooner than most people would think. But I think the bean counters at Apple decided that 9 fans controlled by a computer were cheaper and more accepted than a water cooled system. How many people that rely on their systems a lot are willing to be the first to buy a new water cooled system.
post #62 of 220
....sorry, you'll never see a water cooled machine made by Apple. If it gets to the point where air-cooled heat sinks won't do the trick, I'm sure by that point electron tunneling will be perfected. Electron tunneling cooling is the future.

BTW, the 9 fans are there because 9 runing at very low speed are much quiter than 2 running at high speed.
post #63 of 220
Maybe you guys need to actually take a look at a water cooled system . It definitely has a few fans on it on the radiator, don't know how noisy they are. In this case you get a prebuilt case with the coolant already in it and alot of it set up. You can get simplier setups with just one fan, but would that be enough.
post #64 of 220
Another option to a water-cooled system is a system that is completely submerged in a non-conductive liquid material. Someone showed be a picture of one of these once. It's like a computer in an aquarium. Of course it's definitely not for the consumer, and is probably more of a "see if it works" geek thing.
post #65 of 220
Quote:
Originally posted by Leonard
Another option to a water-cooled system is a system that is completely submerged in a non-conductive liquid material. Someone showed be a picture of one of these once. It's like a computer in an aquarium. Of course it's definitely not for the consumer, and is probably more of a "see if it works" geek thing.

It was probably

Fluorinert

JP.
post #66 of 220
if you want to try the open system (replacing water), can you make the heat pipe spigot a feature?

mmm... espresso mac


as for the best candidate cooling materials...


Aerogel rocks for insulation.
"I do not fear computers. I fear the lack of them" -Isaac Asimov
"I do not fear computers. I fear the lack of them" -Isaac Asimov
post #67 of 220
Aerogel is a great insulator but not so hot for conducting heat away from the chip

It is still very cool stuff though

(Excuse the puns )
post #68 of 220
Quote:
Originally posted by JP
Aerogel is a great insulator but not so hot for conducting heat away from the chip

It is still very cool stuff though

(Excuse the puns )

if no pun was intended, then no punishment.

Aerogel wins for Best Insulator.

Best Conductor? i'm inclined to say... von Karajan
"I do not fear computers. I fear the lack of them" -Isaac Asimov
"I do not fear computers. I fear the lack of them" -Isaac Asimov
post #69 of 220
One point that is being missed. One important point. Liquid cooling is not used just because it removes more heat in a given amount of time. It is also because it tends to equalize the temperature in a system. In other words, minimize hot spots.

Take an engine. If the heat were equally spread throughout the engine, water cooling may not be necessary. But with some parts say, 600° and others 300°, there's the problem. Exhaust valves get a lot hotter than the intake area. Liquid keeps these hot spots from getting to the point of damage.

No I dont know anything about chips, but I'd be surprised if there weren't certain spots on them that were danger points--specific places that will "die" first when heat isnt removed quickly enough.

Liquid could be channeled to this point and spread out. And to a user, the laptop could actually feel warmer than an air cooled one. But key points are kept from critical temps. So you wouldnt necessarily need a huge radiator. Just spreading the heat around makes much more of the computer a radiator. Its all a big heat sink then.

Finally, don't dismiss the idea just because "if it were a good idea, it would be in place now". Take motorcycles. Before you all were born I was riding bikes that were ALL air cooled. Now virutally all sport bikes are liquid cooled. And they're obscenely fast. Like tomorrow's computers.?

So maybe, just maybe.
post #70 of 220
I don't think I am going to touch the licquid cooling subject with a 10 foot pole. However, distilled water will not conduct any electricity (no free charged ions to transmit energy). You could run a computer just fine inside a tank of ion free water. I feel there may be a new advancement in heat sink technology before licquid cooling becomes necessary. Some companies may even resort to running the processor outside of the main box with the heatsinks running out the back. Id like to see a heatsink made like a porous sponge configuration, like that of cancellous bone. This would lead to greater surface area and therefore more passive heat disipation. But then again who knows... but I think I can say its not going to be coolchips

A@ron
post #71 of 220
Quote:
Does it have to be child's play? I don't think anything about the G5's engineering would be considered child's play.

I disagree completely. If there's anything more simplistic than "let's make the case a huge metal heatsink with openings in the back and front and regulate airflow at the sacrifice of practical use" with regard to case design to get around heat issues I don't know what it is. You do not get more "child's play" than "MAKE IT BIGGAR!"

The thing is like one of those Chow dogs that is 90% hair.

The fact that they had to remove features from the previous tower shows that there is a problem. A problem obviated to a large extent by the power of the components being cooled, of course.

The solution of giant metal cases to encourage proper airflow is not something unique to Apple's genius design team. But by all means, let's fellate Jon Ives for putting a cheese grater on the front of a Coolermaster and a neato plexi-glass side on the case (*ahem*) and using lots of fans to cool things. But it's got an Apple logo on the side so obviously they invented all of it. heh

Liquid cooling is absolutely the way of the future, and lambasting iSegway for pointing out this truth is silly when you note that the functionality of the G5 has been cut down from El Capitan because a more innovative/creative way of cooling the components couldn't be found.

Keep one of those fans (and the "oooooo neato" computer control) to push the heat from the radiator out and you can use a much smaller form factor (you wanna tell me the cube wouldn't have benefited?) or properly make use of the amazingly large empty space in the current tower.

But again, the whizz-bang performance of the G5 makes up for the design deficiencies.
proud resident of a failed state
proud resident of a failed state
post #72 of 220
Quote:
Originally posted by reynard
One point that is being missed. One important point. Liquid cooling is not used just because it removes more heat in a given amount of time. It is also because it tends to equalize the temperature in a system. In other words, minimize hot spots.

Take an engine. If the heat were equally spread throughout the engine, water cooling may not be necessary. But with some parts say, 600° and others 300°, there's the problem. Exhaust valves get a lot hotter than the intake area. Liquid keeps these hot spots from getting to the point of damage.

No I dont know anything about chips, but I'd be surprised if there weren't certain spots on them that were danger points--specific places that will "die" first when heat isnt removed quickly enough.

That wouldn't apply to individual chips, but certainly motherboards have hot spots - hard drives, optical drives, CPUs, GPUs, etc.

This is, in fact, pretty much the best case for liquid cooling. For it to work, however, the cooling system has to be designed around certain components in certain places having certain temperatures. Your motorcycle engine doesn't have PCI slots, or replaceable GPUs, or drive bays. This is why Hitachi debuted their liquid cooling in a laptop: For all practical purposes it's a sealed box, and so it's an easier nut to crack. It probably doesn't hurt, either, that none of the components are particularly hot. The Hitachi is modestly spec'd.

So what does this offer the PowerMac? Not much. The system it has now only has to know about heat within four zones, so wildly variable parts like AGP cards won't throw it off, and it has all the airflow it wants because of the "cheese graters". It's overengineered, so you could probably overclock the processors, stick in a couple of 10K drives and stuff the slots full of smoldering 12" cards and the factory cooling system would still hold up (although I imagine it'd be making a racket by then).

I suppose you could have a hybrid system, where things that don't change much are liquid cooled and things that do are fan cooled, but that just makes things more complicated. Apple's system involves very few parts, keeps all the upgradeable bits easily accessible, and it's robust enough to cool the average shipping system by idling. That might not be the greatest imaginable solution (and it's certainly not original - this technique is common in servers), but I don't see how it's stupid or seriously lacking.
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post #73 of 220
How's about this?

You take the permanent features of the board that get hot (namely, processors (which are the biggest problem)) and get them going with direct liquid immersion cooling. Best part, since you've decided to make the case out of aluminum you use the entire giant case as the radiator (or at least the parts nearest the processors). Have a fan nearby (computer-controlled) in case of emergencies if you like. Do the same with the power supply maybe.

Specific application to the G5 would be removal of the giant fans in the lower section of the case.



But the idea of liquid cooling, of course, isn't restricted to the G5 and is still very applicable to Apple because for the most part, Apple makes "closed" systems. The portable line, the iMac and the eMac are all essentially fixed in their configurations. Why would it be hard to put DualG5s in an iMac? Heat. Could a liquid cooling solution fix that? You betcha.

The argument isn't what is cost-efficient or what is smartest for Apple, it's just that it would work. The cheapest solution works for Apple, and that's what giant empty cases are.

I love this image:


It's got ugly cables because you can plug them into internal expansion devices! heh
proud resident of a failed state
proud resident of a failed state
post #74 of 220
Quote:
Originally posted by groverat

Specific application to the G5 would be removal of the giant fans in the lower section of the case.

You don't want to get rid of the giant fans, though, because they can spin slowly and still move lots of air. If you want to control noise, you want to get rid of high RPM fans, and the smaller a fan is the faster it has to run to move the same amount of air.

In the G5, the default speed for the big fans is 1/10 normal speed. That's basically a low whisper. In case of emergency, you still want giant fans, because if pressed they can move tremendous amounts of air - and most people would prefer the resulting roar to a meltdown, if it came to that.

Quote:
But the idea of liquid cooling, of course, isn't restricted to the G5 and is still very applicable to Apple because for the most part, Apple makes "closed" systems.

Absolutely. Apple has shown a willingness to try out interesting cooling methods in the PowerBooks and the Cube and the iBook, because you have a lot more options when you know exactly which components will be how much of a problem when. The Hitachi does not make liquid cooling look particularly attractive, though. Compare its price to its specs. Apple seems to have done quite well combining passive cooling with tactfully placed fans, so the question is not whether liquid cooling would work - obviously it works - but whether it works better, and how much it costs.

And this is quite different from the original hope that liquid cooling could allow the PowerMac G5 to be more internally expandable.

Quote:
The portable line, the iMac and the eMac are all essentially fixed in their configurations. Why would it be hard to put DualG5s in an iMac? Heat. Could a liquid cooling solution fix that? You betcha.

Heat and cost and space, actually. But I'm not entirely convinced that liquid cooling could do that. Remember, liquid mostly just moves the problem around - which is not a bad thing. In the iMac, there aren't too many places to move to, and any active cooling (refrigerator or fan) would defeat the purpose. Maybe Apple could try spiraling a tube around the dome, cooling tower style? If they had dual G5's in there the dome would have to be aluminum, but it might work...
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post #75 of 220
...why not just use this....

...besides, with 90nm, 65nm on the horizon, I doubt we'll run into a need for liquid cooling any time soon for the mass market. Apple's solution is more about noise control than heat control. Remember that.

Cool Chips
post #76 of 220
Amorph:

Quote:
You don't want to get rid of the giant fans, though, because they can spin slowly and still move lots of air. If you want to control noise, you want to get rid of high RPM fans, and the smaller a fan is the faster it has to run to move the same amount of air.

I'm talking specifically in that area of the G5. to make room for more expandability options (5.25" drive bays and hard drive racks). With the processors cooled by liquid immersion there is no need to cool them with fans.

Quote:
In the G5, the default speed for the big fans is 1/10 normal speed. That's basically a low whisper. In case of emergency, you still want giant fans, because if pressed they can move tremendous amounts of air - and most people would prefer the resulting roar to a meltdown, if it came to that.

I know. But that's a lot of real estate.

Quote:
The Hitachi does not make liquid cooling look particularly attractive, though.

Well you'll notice I didn't mention the Hitachi as a method to follow. And just because that doesn't look attractive there is no implication that it is not possible or even reasonable.

Quote:
Apple seems to have done quite well combining passive cooling with tactfully placed fans, so the question is not whether liquid cooling would work - obviously it works - but whether it works better, and how much it costs.

Cost is an issue for Apple, I'm not talking about real prices because neither you nor I really know either way.

As far as Apple doing "quite well" in the cooling arena, have you ever tried using a modern PowerBook on your lap? Yikes.

Quote:
And this is quite different from the original hope that liquid cooling could allow the PowerMac G5 to be more internally expandable.

Liquid cooling provides many options.
For $2900 is it unreasonable to scratch your head at the lack of drive bays?

Quote:
Remember, liquid mostly just moves the problem around - which is not a bad thing.

Better out the back of the laptop than directly and "elegantly" on your flesh.

Quote:
In the iMac, there aren't too many places to move to, and any active cooling (refrigerator or fan) would defeat the purpose. Maybe Apple could try spiraling a tube around the dome, cooling tower style? If they had dual G5's in there the dome would have to be aluminum, but it might work...

You could even cool the liquid passively provided a small pump for forced circulation through the hottest portions of the machine.

Apple is borrowing a page from the performance PC nerds with their giant metal heatsink case and plexiglass side door for super-cool looking at the innards. One can only wonder if they follow the trend of liquid cooling.
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post #77 of 220
From the apple developper note about the G5 page 12 :

Power supply : The Power Mac G5 computer comes with either a 450 w or 600 w power supply.

I think it's the biggest power supply ever in a powermac.

Big power supply means, more heat ( a big power supply imply in itself more heat). I think there is no absolutely no chance to make work a G5 system in the old case. A G5 require more power supply to feed the chips, and to feed the mobo. Watercooling is used to cool the CPU and some ASICS or video card. I never heard of a watercooled powersupply. And i am ready to bet that a 600 watts powersupply produce a lot of heat.
post #78 of 220
600w!?

Are we sure Jon Ives isn't a frequent visitor of Tom's Hardware, HardOCP or ArsTechnica?
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post #79 of 220
Quote:
Originally posted by groverat
I'm talking specifically in that area of the G5. to make room for more expandability options (5.25" drive bays and hard drive racks). With the processors cooled by liquid immersion there is no need to cool them with fans.

I'm with you on the need/desire for more drive bays, but liquid cooling doesn't mean no fans. It does mean less fans though. In a liquid cooled machine, the liquid pulls the heat to a concentrated location where a fan still has to blow the heat out of the box. I think that's what Amorph was trying to say.
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post #80 of 220
Thread Starter 
Quote:
I'm with you on the need/desire for more drive bays, but liquid cooling doesn't mean no fans. It does mean less fans though.

I disagree with this.... IMO water cooling can be acheived without fans... the question is would people pay the extra money for a totally silent computer and deal with the larger radiator and/or water resevoir it would require? I would... but I could see others not wanting to.



http://www.popularmechanics.com/tech...3/index5.phtml


TEXT AND PHOTOS BY JONATHAN GROMER

As processors get smaller and packed with more transistors for greater speed, the problem of heat becomes a crisis. Chip temperatures are approaching the limits of existing cooling technology, and too much heat is a common killer of computers' central processors. High-power processors already generate between 40 and 70 watts of thermal energy, and much more powerful 64-bit processors will be on our desks in the immediate future. By the end of this decade, because of increasing chip speeds--and a corresponding increase in temperature--it's estimated that a square centimeter of microprocessors could generate upward of 1000°F--equivalent to the exhaust temperature of the rockets on the space shuttle. We need a new cooling solution--and soon. CoolIT Systems, a small company out of Calgary, Canada, might have just introduced the answer: a liquid-cooling system.

The CoolIT system isn't the first to use a liquid-based approach. Considerably more expensive than air-cooling systems ($200 more by average), liquid cooling has been available for years, thanks to the distinct advantage of being able to transfer much more heat away from a processor than an air-based system.

Look inside your computer and you'll find the MVP of your air-cooling system: a piece of metal designed with a lot of surface area (usually fins), coupled to your processor. This metal structure is a heat sink, usually made of copper, drawing dangerous heat away from your hot-blooded chip. A fan blows a steady stream of air onto the heat sink to cool it down, and allows it to absorb more heat from your processor. High-speed processors need high-performance fans that sometimes pump out 60-plus decibels of noise--and some systems have up to five fans.

Water, however, is 10 times more effective than copper as a coolant, making it a superior choice. Liquid cooling is also much quieter than air cooling. Although liquid cooling still requires a fan, it doesn't need one strong or loud enough to make you feel like you have a model airplane under your desk.

So with these great advantages, why can't you buy a computer with a liquid-cooling system already installed? First off, liquid-cooling systems are bulky. A radiator is used to send the heat absorbed by the water out of the box. If you don't have your radiator someplace cooler than the room's ambient temperature (like on a window sill or in a refrigerator), you'll need fans to cool it off. And radiators are big. A smaller, more portable radiator needs louder, more powerful fans. Add the fact that many liquid-cooled systems are heavy because of the volume of water needed, and the cost benefits of liquid-cooling systems just don't stack up to air-cooling systems. Not to mention that you could soak your electronics or give yourself a severe shock if you don't install the system properly.

The CoolIT system shines because it offers the strengths of a liquid-cooled system in a small and simple package. Instead of an attention-hungry radiator, the CoolIT system uses a self-contained device called a Chiller that drops water to below ambient temperatures like a refrigerator. The Chiller uses peltier cooling, a special heat sink and a fan. Peltier cooling is a thermoelectric principle whereby one direction of an electric current allows heat to be absorbed on one side of a metal device (making it cold) as heat is rejected on the opposite side (making it warm).

The small size of the Chiller allows for a portable, smaller form factor and the fan of the prototype unit we're using is relatively quiet--with a quieter prototype in development as this is being written. As for liquid cooling's weight problem, the CoolIT system requires only 140cc to 170cc of liquid and one pump to send it through the system's tubes. Best of all, you can buy a CoolIT system on a commercially available machine--boutique builder Voodoo Entertainment Systems will be offering CoolIT systems on its premium F-1 machines in fall 2003 for a price that will range between $5000 and $6000. The price may seem a little high, but it's important to remember that every 10° drop in operating temperature should double your CPU's expected useful life.

Our tests showed that the CoolIT unit kept our Voodoo F-1 system 4°F cooler inside the box than the room temperature outside while under heavy stress--unheard of with conventional air cooling. Even CoolIT's own test numbers don't reflect such high performance.

For more information on CoolIT Systems, contact Ravi Sood at Voodoo Entertainment Systems: 888-708-6636 or www.voodoopc.com.


Thick tubes of cool blue liquid connect all the components of the CoolIT system in our prototype Voodoo F-1. The black box at the top of the unit is the innovative Chiller.




The gray box with three tubes entering it houses the system's pump and voltage inverter. The metal square with two tubes on the right of the box is the heat exchanger for the CPU. The metal plate on the card below pulls heat away from the graphics-processing unit.
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