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.
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.
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.
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.
Quote:
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.
Quote:
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?
Quote:
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?
Quote:
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.
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.
Quote:
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.
Quote:
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)
Quote:
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.
Quote:
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.
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.
Quote:
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.
Quote:
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!
Quote:
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.
Quote:
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.
Quote:
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.
Quote:
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.
Quote:
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.
Quote:
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.
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?
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.
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.
Quote:
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.
Quote:
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?
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.
Quote:
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.
Quote:
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.
Quote:
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.
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.
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.
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?
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.
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.
[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.
Comments
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.
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.
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.
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.
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.
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?
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?
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?
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.
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.
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)
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.
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.
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.
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.
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!
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.
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.
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.
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.
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.
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.
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.
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?
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?
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.
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.
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.
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?
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.
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.
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.
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.
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.
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.
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?
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.
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.
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.