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Mac Forum / General / Hardware / July 2007Mac Mini heat sink upgrading?
Has anyone heard of someone changing the heat sink on their Mini? My PPC 1.25 ghz model would need a heat sink not exceeding 47 mm x 118 mm. (47 mm is about 1.5 inches.) A Sonic Tower might work if one ground the 2 of the sides but it would be great to get a good one that might fit (with some retrofitting of course to mount it). In article <replytogroup-577521.10140527062007@news.lga.highwinds-media.com>, > Has anyone heard of someone changing the heat sink on their Mini? No one in their right mind.  SignatureSupport the troops: Bring them home ASAP. > > Has anyone heard of someone changing the heat sink on their Mini? > > No one in their right mind. I never implied I was in my right mind. So Micheele, did you look into the transferring costs with your current cell provider to extricate yourself out of your contract? I seem to remember a website that does nothing but find people to take over contracts of other people that don't need them anymore. You'd have to Google that. I should have included that in the original reply but forgot. In article <replytogroup-577521.10140527062007@news.lga.highwinds-media.com>, > Has anyone heard of someone changing the heat sink on their Mini? My > PPC 1.25 ghz model would need a heat sink not exceeding 47 mm x 118 > mm. (47 mm is about 1.5 inches.) A Sonic Tower might work if one > ground the 2 of the sides but it would be great to get a good one that > might fit (with some retrofitting of course to mount it). What would be the purpose of doing this? Would this reduce the fan noise from my PPC 1.25 ghz Mac Mini? Regards, John Byrns SignatureSurf my web pages at, http://fmamradios.com/ > In article > <replytogroup-577521.10140527062007@news.lga.highwinds-media.com>, [quoted text clipped - 7 lines] > What would be the purpose of doing this? Would this reduce the fan > noise from my PPC 1.25 ghz Mac Mini? Disregard The New Guy. The guy is obsessed with heat sinks, and is under the mistaken belief that all Macs are insufficiently cooled. SignatureJR > > Has anyone heard of someone changing the heat sink on their Mini? My > > PPC 1.25 ghz model would need a heat sink not exceeding 47 mm x 118 [quoted text clipped - 4 lines] > What would be the purpose of doing this? Would this reduce the fan > noise from my PPC 1.25 ghz Mac Mini? Yes John. It would dramatically reduce it. The same way good heat sinks dramatically reduce the noise of fans in any computer. But for now, try what another poster did: place it vertically so the bottom can dissipate heat better. The ultimate would be to place it on a cold surface. The slot loading optical drive should have no problems operating in a vertical position, as far as I know. Which isn't very far. The Mini uses a small fan, similar to what you find on some video cards so when its going hard its really irritating. That's what I'm really trying to get away from; the pitch of the whine more than anything. >> What would be the purpose of [putting in a larger heat sink]? Would >> this reduce the fan noise from my PPC 1.25 ghz Mac Mini? > Yes John. It would dramatically reduce it. The same way good heat > sinks dramatically reduce the noise of fans in any computer. John, As Jolly Roger has said, be wary of what "The New Guy" has to say about cooling in general and heat sinks in particular. It's not that TNG is absolutely wrong about absolutely everything, but he is remarkably confused about fundamentals in such a way that a little knowledge really is dangerous. I most certainly don't want to repeat the discussion that has already taken place, but you can go back a few weeks and look the discussion he started about iMac cooling. -j > >> What would be the purpose of [putting in a larger heat sink]? Would > >> this reduce the fan noise from my PPC 1.25 ghz Mac Mini? [quoted text clipped - 11 lines] > taken place, but you can go back a few weeks and look the discussion he > started about iMac cooling. How about not trying to sabotage a thread? I simply asked if anyone has heard of the Mini heat sink being upgraded. The answer is a Yes or a no-answer. If its a Yes, hopefully an URL will follow so I can learn about it. Surely this hardware deficient newsgroup can grapple with that simple task. In article <replytogroup-250C73.18342527062007@news.lga.highwinds-media.com>, > How about not trying to sabotage a thread? > I simply asked if anyone has heard of the Mini heat sink being > upgraded. The answer is a Yes or a no-answer. If its a Yes, > hopefully an URL will follow so I can learn about it. Surely this > hardware deficient newsgroup can grapple with that simple task. Because you asserted in a subsequent post that the change make a hugely positive impact, and you are woefully under-qualified to make a statement like that. If all you were interested in was an answer to your question, you wouldn't have attempted to shove bad advice down someone else's throat. Leaving that as is would be extremely irresponsible. In short, you sabotaged your own thread. Next time if all you want is an answer, don't offer bad advice in a follow-up. In article <sdfisher-2A4843.17071227062007@shawnews.vc.shawcable.net>, > In article > <replytogroup-250C73.18342527062007@news.lga.highwinds-media.com>, [quoted text clipped - 8 lines] > positive impact, and you are woefully under-qualified to make a > statement like that. I would propose that if a statement is true or false, the credibility of the person making that statement is irrelevant. All the matters is the truth of the statement. Some of you are well educated in science yet lack real world experience so you don't recognize where the priorities lie in the computer cooling world. I don't want to dig up what was amply discussed before though. > If all you were interested in was an answer to your question, you > wouldn't have attempted to shove bad advice down someone else's throat. > Leaving that as is would be extremely irresponsible. What bad advice are you talking about? In article <replytogroup-EEA8A5.14343228062007@news.lga.highwinds-media.com>, > > Because you asserted in a subsequent post that the change make a > > hugely positive impact, and you are woefully under-qualified to [quoted text clipped - 3 lines] > of the person making that statement is irrelevant. All the matters > is the truth of the statement. That is correct; however, when the truth of the statement is not self evident, the credibility of the person making it comes into question. And when the person making the statement has demonstrated repeatedly that he doesn't know much, if anything, about the topic, his credibility is very much an issue. > Some of you are well educated in science yet lack real world > experience so you don't recognize where the priorities lie in the > computer cooling world. You have demonstrated lack of education in the field as well as lack of real-world experience, nor have you shown any cognizance of what the priorities are. In other words, you don't know what you're talking about again. SignatureSupport the troops: Bring them home ASAP. > > > Because you asserted in a subsequent post that the change make a > > > hugely positive impact, and you are woefully under-qualified to [quoted text clipped - 6 lines] > That is correct; however, when the truth of the statement is not self > evident, the credibility of the person making it comes into question. If people were knowledgeable on a subject, the truth of the statement would be evident. So it all comes down to real world experience. > > Some of you are well educated in science yet lack real world > > experience so you don't recognize where the priorities lie in the [quoted text clipped - 5 lines] > > In other words, you don't know what you're talking about again. Your opinion, Michelle. Like I've said, you know software very well. In hardware your knowledge just isn't there. In real world experience, less so. Maybe you just can't stand it when someone disagrees with you? In article <replytogroup-E5EA25.15161228062007@news.lga.highwinds-media.com>, > > > > Because you asserted in a subsequent post that the change make a > > > > hugely positive impact, and you are woefully under-qualified to [quoted text clipped - 24 lines] > experience, less so. Maybe you just can't stand it when someone > disagrees with you? No, just the opinion of everyone of this NG who has two braincells to rub together, a department in which you were sadly short-changed. In article <replytogroup-E5EA25.15161228062007@news.lga.highwinds-media.com>, > > > > Because you asserted in a subsequent post that the change make a > > > > hugely positive impact, and you are woefully under-qualified to [quoted text clipped - 24 lines] > experience, less so. Maybe you just can't stand it when someone > disagrees with you? Ya know, you keep saying that. But looking back at that thread about heat sinks, I can't find one single person that agrees with you. Why does that not tell you something? If you're so right, how can everyone else be so wrong? Maybe you just can't stand it when _everyone_ disagrees with you. Ruby. Signature"Rarely is the question asked: is our children learning?" -- George W. Bush > In article > <replytogroup-E5EA25.15161228062007@news.lga.highwinds-media.com>, [quoted text clipped - 34 lines] > > Maybe you just can't stand it when _everyone_ disagrees with you. Not at all. Like I said, the hardware experience here is not strong. The software experience here is very strong. Actually there were several people that agreed with several of my points. Once Michelle and others starting slinging insults than others jumped on the bandwagon. It happens. No biggee. And its not about someone "agreeing with you" on everything. Its about specific points. My experience gave me knowledge and now I know why certain designs are lacking. If someone else doesn't have that experience, they may not agree with me. Perfectly understandable. But we're getting off track. This thread is simply about if anyone has read or heard of the Mini heat sink being replaced. I Googled but didn't have much luck. >> Maybe you just can't stand it when _everyone_ disagrees with you. > > Not at all. Like I said, the hardware experience here is not strong. You have no evidence to back up that opinion - and it is just an opinion. Some of us do have substantial hardware experience. > The software experience here is very strong. As is the hardware experience. > My > experience gave me knowledge and now I know why certain designs are > lacking. If someone else doesn't have that experience, they may not > agree with me. Perfectly understandable. Exactly what experience do you have? What degrees do you hold? SignatureJR > >> Maybe you just can't stand it when _everyone_ disagrees with you. > > > > Not at all. Like I said, the hardware experience here is not strong. > > You have no evidence to back up that opinion - and it is just an > opinion. Some of us do have substantial hardware experience. My evidence is what people say about hardware here. That's just my opinion of course. You're may differ. No problem. Its a free country, right? > > The software experience here is very strong. > > As is the hardware experience. If you want to believe that, fine. > > My > > experience gave me knowledge and now I know why certain designs are > > lacking. If someone else doesn't have that experience, they may not > > agree with me. Perfectly understandable. > > Exactly what experience do you have? What degrees do you hold? Real world experience. Trying different things and seeing their effect. The only thing that matters is results. And I get results in my own equipment. Look at the medical profession. Here you have highly educated professionals that are almost useless for anything but trauma (accidents). In disease, they are useful for little more than diagnosis. They are highly trained, and by society's definition, highly educated. Yet they largely responsible for our society's disgraceful health condition. If you told them "I ate something different and noticed these health benefits", they wouldn't listen. Or 99% wouldn't. They are simply not willing to step out of the mainstream and risk ridicule by their peers by noticing something different. You will almost never hear a medical doctor ever recommend fasting yet that has helped untold numbers of people cure terminal health conditions. In some ways education can hinder people. It traps them in established ways of thinking. Results are the only thing that matters. Before I gave results showing very effective and silent cooling options. Temperature results. The only thing that matters. A lot of you think that exhausted hot air is not a sign of poor cooling. I guess that could be true if you believe that components and their heat sinks can run at far higher temperatures than typical room temperature with no long term problems. Most electronics experts will attest to the fact that you want to run electronics at as cool a temperature as possible or as close to room temperature as possible. This is indeed possible and can be tested simply by holding your hand and feeling the exhausted air. If it feels warm, that means its a lot higher then room temperature. Cooling can be quite easy. Some techniques may seem a little unorthodox, but they are not costly and they really work. In article <replytogroup-612238.18034528062007@news.lga.highwinds-media.com>, > > You have no evidence to back up that opinion - and it is just an > > opinion. Some of us do have substantial hardware experience. > > My evidence is what people say about hardware here. That evidence goes against your opinion. > > Exactly what experience do you have? What degrees do you hold? > > Real world experience. Trying different things and seeing their > effect. The only thing that matters is results. And I get results > in my own equipment. In other words, nothing worthwhile. > Before I gave results showing very effective and silent cooling > options. Temperature results. The only thing that matters. You didn't measure the right things, and your interpretation of your results is screwy. SignatureSupport the troops: Bring them home ASAP. > > > Exactly what experience do you have? What degrees do you hold? > > [quoted text clipped - 3 lines] > > In other words, nothing worthwhile. Well if you call cooling at near ambient levels nothing, so be it. Its the pinnacle of simple, air cooled, cooling, nevertheless. Nobody wants to rely on liquid cooling if they don't have to. The air being exhausted out of my machines feel the same as the ambient temperature. That's cooling that works. And its near silent almost all the time. And the only thing that isn't silent is that tiny Mini fan. That's why I'm searching for a better heat sink. > > Before I gave results showing very effective and silent cooling > > options. Temperature results. The only thing that matters. > > You didn't measure the right things, and your interpretation of your > results is screwy. I didn't measure anything at all. You don't even remember. If you go back to that thread that would never die, you will see that I gave an example of a siltentpcreview article that also showed near ambient levels of cooling that were far lower than the ones supplied by Jolly Roger's iMac and G5 Tower. It wasn't my figures. Remember, I don't have temperature sensors in my Mini. But any idiot knows that the cooling is working if the exhausted air is cool. Michelle, you seem exceedingly angry lately. Maybe some more cardio would relieve some of the angst? > any idiot knows that the > cooling is working if the exhausted air is cool. No, cooling is working if the temperature of the components being cooled is low. The temperature of the exiting air is insignificant. You have a lot to learn, my friend. SignatureJR > > any idiot knows that the cooling is working if the exhausted air is cool. > > No, cooling is working if the temperature of the components being > cooled is low. The temperature of the exiting air is insignificant. > > You have a lot to learn, my friend. Well, that was polite at least. Now would someone please enlighten me on how a component can be cooled at near ambient levels and the exhausting air is hot. This is supposing that we're in a normal enclosure that doesn't trap air of course. In article <replytogroup-477292.21181528062007@news.lga.highwinds-media.com>, > Now would someone please enlighten me on how a component can be > cooled at near ambient levels and the exhausting air is hot. The heat transfers from the component, heating the air, and the air then leaves the enclosure. That is a concept that you refuse to understand. SignatureSupport the troops: Bring them home ASAP. > In article > <replytogroup-477292.21181528062007@news.lga.highwinds-media.com>, [quoted text clipped - 4 lines] > The heat transfers from the component, heating the air, and the air then > leaves the enclosure. That is a concept that you refuse to understand. It is impossible for the heat sink to be at a lower temperature than the exiting air that is removing its thermal energy. Isaac >> In article >> <replytogroup-477292.21181528062007@news.lga.highwinds-media.com>, [quoted text clipped - 7 lines] > It is impossible for the heat sink to be at a lower temperature than the > exiting air that is removing its thermal energy. True in the strict sense, but you're not taking into account that some systems funnel heated air from multiple components into a single air channel before final exit. SignatureJR > >>> Now would someone please enlighten me on how a component can be > >>> cooled at near ambient levels and the exhausting air is hot. [quoted text clipped - 5 lines] > systems funnel heated air from multiple components into a single air > channel before final exit. And that design is going to be relegated to the scrap heap more and more, the Mac Pro case design being a good start. The trouble is the shape of the typical motherboard. Instead of about 12" x 9" (108 square inches), it could be maybe 18" x 6 " or whatever the maximum depth needed for the longest PCI card. A large fan (250 mm or about 10") on the bottom would push air up and ductwork would conduct the air into each area. You could have separate channels for the CPU heat sink, Video card(s), ram and chipset(s). Then the hard drives (2 fixed for Raid 0 for the OS and Programs and others in removable hard drive drawers for data) could be mounted on the other side of the motherboard with a channel of air for them. But to reshape motherboard design......that would take a lot of convincing. Sort of like reinventing the wheel. If they just oriented the ram so it was in the same direction as the PCI slots, that would help a lot. The CPU channel would be still be at the far right, then maybe the ram and chipsets, then the PCI slots. With ram getting hotter and hotter, (note the heat sinks on most all high end ram), it just makes sense to cool it with some airflow. But not like the Mac Pro using the hot CPU heat sink air to cool the FB-Dimm ram heat sinks. We may see some very different case design come about once 250 mm or larger fans become more common. > > > Now would someone please enlighten me on how a component can be > > > cooled at near ambient levels and the exhausting air is hot. > > It is impossible for the heat sink to be at a lower temperature than the > exiting air that is removing its thermal energy. Yes, that's kind of obvious. Nowhere did I intimate that that was not true. But it IS very much possible for the heat sink to be NEAR ambient temperature levels. VERY near. But this bring up an interesting question that you engineers can answer. When we go outside, the higher the wind, the lower the temperatures feels. Is it ever possible that a similar thing happens with inanimate objects? You take a heat sink with nothing heating it, then you blast it with, say, 70 F room temperature air. Can the temperature of the heat sink ever get lower than 70 F? It FEELS colder in a wind to us, but what about the actual temperature solid structures? I think someone mentioned before that we feel cool because of the rate of evaporation from our skin. I'm not sure if that applies here but of course solid structures have no evaporation rate. >>>> Now would someone please enlighten me on how a component can be >>>> cooled at near ambient levels and the exhausting air is hot. [quoted text clipped - 16 lines] > that applies here but of course solid structures have no evaporation > rate. No they will not cool lower than 70 F. There is no evaporative action, which is what is happening to your stupid hand when you feel the exit air. This whole thing is how you FEEL about it. Check out some thermodynamic laws about heat transfer. Do you know "easy" it is to transfer heat from one object at 26C to ambient air of 25C? If the incoming air is 25C and the exit air is 25C just how much heat is being removed from the system? SignatureGrandpa In article <replytogroup-C03557.12504529062007@news.lga.highwinds-media.com>, > > > > Now would someone please enlighten me on how a component can be > > > > cooled at near ambient levels and the exhausting air is hot. [quoted text clipped - 17 lines] > that applies here but of course solid structures have no evaporation > rate. No; the cooling effect you observe under those conditions is mostly due to evaporation of the moisture on the skin. Inanimate object do not perspire. The heat of vaporization of water is approximately 539 cal/gram. Even if such objects did perspire, no amount of airflow would cool them below the temperature of the air passing over them; the moisture would just not vaporize. You would do well learn a little about partial pressures and thermodynamic equilibrium. In article <replytogroup-C03557.12504529062007@news.lga.highwinds-media.com>, > When we go outside, the higher the wind, the lower the temperatures > feels. Not always. Try going out in the 110 (+/- 5) degree temperature here in Phoenix on a windy day. The temperature feels hotter than if there were no wind. SignatureSupport the troops: Bring them home ASAP. > In article > <replytogroup-C03557.12504529062007@news.lga.highwinds-media.com>, [quoted text clipped - 5 lines] > Phoenix on a windy day. The temperature feels hotter than if there were > no wind. I recall Orlando at 100F, 98% humidity, and smoke from forest fires covering the city. No amount of wind could have made a difference. Same in Nawlins... And Atlanta... > > When we go outside, the higher the wind, the lower the temperatures > > feels. > > Not always. Try going out in the 110 (+/- 5) degree temperature here in > Phoenix on a windy day. The temperature feels hotter than if there were > no wind. Reminds me of when I was driving through the desert in the evening and the temperature was over 100 F. You're right, it did feel like it was heating my skin. I guess that was because it was above body temperature. It sure felt eerie the first time. > > Now would someone please enlighten me on how a component can be > > cooled at near ambient levels and the exhausting air is hot. > > The heat transfers from the component, heating the air, > and the air then leaves the enclosure. That is a concept > that you refuse to understand. My point all along is if the heat sink is properly designed for the task, it will hardly get warm. So it really can't heat the air as long as their is reasonable airflow aided by a fan. It all boils down to the job the heat sink is doing since we never operate in sealed boxes - there is always airflow. Now if the heat sink is barely getting warm, it doesn't heat the air so the exiting air is near ambient temperature. So exhausted air temperatures are very indicative of cooling efficiency, hard as that may be to accept for some of you. >Now would someone please enlighten me on how a component can be cooled >at near ambient levels and the exhausting air is hot. This is >supposing that we're in a normal enclosure that doesn't trap air of >course. Free clue: No one cools a component to "near ambient levels". It's both impractical and unnecessary. SignatureThere's no such thing as a free lunch, but certain accounting practices can result in a fully-depreciated one. > >Now would someone please enlighten me on how a component can be cooled > >at near ambient levels and the exhausting air is hot. This is [quoted text clipped - 3 lines] > Free clue: No one cools a component to "near ambient levels". It's > both impractical and unnecessary. Free clue: I do. Its done quite easily using exterior air and venting it immediately so the heat doesn't rise in the enclosure. Now whether you believe its necessary, that up to you. But its very practical indeed. ...... >> Free clue: No one cools a component to "near ambient levels". It's >> both impractical and unnecessary. [quoted text clipped - 3 lines] >whether you believe its necessary, that up to you. But its very >practical indeed. Post your measurements of the component and temperature of exhaust air. Measure this for several values of airflow. > >> Free clue: No one cools a component to "near ambient levels". It's > >> both impractical and unnecessary. [quoted text clipped - 6 lines] > Post your measurements of the component and temperature > of exhaust air. Measure this for several values of airflow. I'm shopping around for an infrared type thermometer. But I'll have to test it with a machine that has built in sensors to make sure its calibrated correctly. Unless you can look it up, the sensors are not exactly obvious on the motherboard, are they? And would the temp of the motherboard itself influence the ambient air reading? Sort of like mounting a thermometer outside on a surface that gets hot or cold. Its probably going to influence the reading. I hope to avoid inaccuracies like that. In article <replytogroup-4AF686.10375302072007@news.lga.highwinds-media.com>, > > >> Free clue: No one cools a component to "near ambient levels". It's > > >> both impractical and unnecessary. [quoted text clipped - 15 lines] > that gets hot or cold. Its probably going to influence the reading. > I hope to avoid inaccuracies like that. I can't say about the mini and its CPU in particular, but it's common for the temperature sensor to be built into the CPU chip itself. It's just another transistor, wired in a special way. You can find little apps that can give you a readout from it. And remember, it will be measuring the temperature of the active surface of the processor directly, so it'll be considerably warmer than any external surface you can stick a thermometer on. Isaac > > > >> Free clue: No one cools a component to "near ambient levels". It's > > > >> both impractical and unnecessary. [quoted text clipped - 24 lines] > external surface you can stick a thermometer on. > Isaac Thanks Isaac. >> >Now would someone please enlighten me on how a component can be cooled >> >at near ambient levels and the exhausting air is hot. This is [quoted text clipped - 8 lines] >whether you believe its necessary, that up to you. But its very >practical indeed. Q = -hA(Ts - T) SignatureThere's no such thing as a free lunch, but certain accounting practices can result in a fully-depreciated one. > >> >Now would someone please enlighten me on how a component can be cooled > >> >at near ambient levels and the exhausting air is hot. This is [quoted text clipped - 10 lines] > > Q = -hA(Ts - T) That brought me here: http://biocab.org/Heat_Transfer.html A nice summary of correct terminology to help express myself better. Thanks. > >Now would someone please enlighten me on how a component can be cooled > >at near ambient levels and the exhausting air is hot. This is [quoted text clipped - 3 lines] > Free clue: No one cools a component to "near ambient levels". It's > both impractical and unnecessary. Correct. The closer to ambient, the harder the cooling process becomes. Exponentially harder. > > any idiot knows that the > > cooling is working if the exhausted air is cool. > > No, cooling is working if the temperature of the components being > cooled is low. The temperature of the exiting air is insignificant. I agree that it is the "temperature of the components being cooled" that is important, but I don't agree that the "temperature of the exiting air is insignificant", although "The New Guy's" conclusions about the exhausted air don't necessarily follow. Regards, John Byrns SignatureSurf my web pages at, http://fmamradios.com/ > I don't agree that the "temperature of the exiting air > is insignificant" It's insignificant when you consider that the air flow rate is variable. SignatureJR > > I don't agree that the "temperature of the exiting air > > is insignificant" > > It's insignificant when you consider that the air flow rate is variable. Here again airflow is coming into play. Well, unless you don't care about noise, airflow is simply not a factor unless noise is not a factor. Its rather hard, in any design, to have high airflow without significant noise. So if you care about noise, you cannot depend on fans to take care of cooling that the heat sink is not doing. >Here again airflow is coming into play. Well, unless you don't care >about noise, airflow is simply not a factor unless noise is not a >factor. Its rather hard, in any design, to have high airflow without >significant noise. So if you care about noise, you cannot depend on >fans to take care of cooling that the heat sink is not doing. You seem to be under the misconception that the heat sink is doing any cooling at all. It's not. The heat sink is being passively heated by the component. The airflow is effectively doing ALL the cooling (radiation to the environment is not significant); the heat sink itself is just a middleman. SignatureThere's no such thing as a free lunch, but certain accounting practices can result in a fully-depreciated one. > >Here again airflow is coming into play. Well, unless you don't care > >about noise, airflow is simply not a factor unless noise is not a [quoted text clipped - 7 lines] > (radiation to the environment is not significant); the heat sink > itself is just a middleman. I think we're a little beyond these semantics. The point is you need a large, well designed heat sink to get that heat away from the heat generator. The better the heat sink, the less airflow you need. Now it just happens that 120 mm and larger fans fit nicely on larger heat sinks. So now many users are finding they can run that 120 mm fan at inaudible speeds and still get good cooling. In article <replytogroup-2A3FB1.12462901072007@news.lga.highwinds-media.com>, > > >Here again airflow is coming into play. Well, unless you don't care > > >about noise, airflow is simply not a factor unless noise is not a [quoted text clipped - 9 lines] > > I think we're a little beyond these semantics. You obviously don't understand what semantics means either. > The point is you need > a large, well designed heat sink to get that heat away from the heat > generator. The better the heat sink, the less airflow you need. This is untrue and underpins your lack of understanding of this subject. > Now > it just happens that 120 mm and larger fans fit nicely on larger heat > sinks. So now many users are finding they can run that 120 mm fan at > inaudible speeds and still get good cooling. > > > >Here again airflow is coming into play. Well, unless you don't care > > > >about noise, airflow is simply not a factor unless noise is not a [quoted text clipped - 13 lines] > > This is untrue and underpins your lack of understanding of this subject. Tim, what exactly was untrue about what I said? > > Now it just happens that 120 mm and larger fans fit nicely on larger heat > > sinks. So now many users are finding they can run that 120 mm fan at > > inaudible speeds and still get good cooling. In article <replytogroup-FA3BE1.18382701072007@news.lga.highwinds-media.com>, > > > > >Here again airflow is coming into play. Well, unless you don't care > > > > >about noise, airflow is simply not a factor unless noise is not a [quoted text clipped - 15 lines] > > Tim, what exactly was untrue about what I said? Isaac said, correctly, that the heat sink is providing an impedance matching between the chip (which is small) and the air (which ultimately carries the heat away). As with any impedance matching device, it has an optimum size. For a given chip producing a certain amount of heat, and a given airflow, there will be more or less one size of heat sink that is correct. Size in this case may simply be nothing more than the surface area due to it having lots of fins. You vary one of the parameters, such as heat produced, and if you want to remain at equilibrium (i.e. constant chip temperature), you better also vary the other parameter you have control over, namely airflow. So we see what is observed, namely the fan speeds up. You optimise the heat-sink size to maximise the heat transfer from the chip to the heat sink, and then to the air. It doesn't necessarily lead automatically to the conclusion that the heat sink is large. > In article > <replytogroup-FA3BE1.18382701072007@news.lga.highwinds-media.com>, [quoted text clipped - 16 lines] > sink, and then to the air. It doesn't necessarily lead automatically to > the conclusion that the heat sink is large. Many of us have tried, in vein, to explain this to The New Guy repeatedly. He refuses to believe it. Good luck with that. SignatureJR > Many of us have tried, in vein, to explain this to The New Guy > repeatedly. <grammar/spelling nazi> "in vain" <end nazi> SignatureSupport the troops: Bring them home ASAP. > > Many of us have tried, in vein, to explain this to The New Guy > > repeatedly. [quoted text clipped - 4 lines] > > <end nazi> Maybe that meant they got so frustrated they cut themselves.. >> Many of us have tried, in vein, to explain this to The New Guy >> repeatedly. > > <grammar/spelling nazi> > "in vain" > <end nazi> Good catch. Thanks. SignatureJR > >> Many of us have tried, in vein, to explain this to The New Guy > >> repeatedly. [quoted text clipped - 4 lines] > > Good catch. Thanks. I can see how you made that error; he is, after all, a blood sucker--metaphorically speaking, of course. SignatureSupport the troops: Bring them home ASAP. > > > > > >Here again airflow is coming into play. Well, unless you don't care > > > > > >about noise, airflow is simply not a factor unless noise is not a [quoted text clipped - 22 lines] > carries the heat away). As with any impedance matching device, it has an > optimum size. Only economically speaking to save money on materials. The bigger the heat sink, all other things being equal, the cooler it will run, simply because more heat is drawn out of the heat generator. Manufacturers use smaller heat sinks to simply save money. Name one top end heat sink that is small! Look at Scythe, Thermaltake and other high end manufacturers. All of their best products are huge. > For a given chip producing a certain amount of heat, and a > given airflow, there will be more or less one size of heat sink that is > correct. Size in this case may simply be nothing more than the surface > area due to it having lots of fins. But the reason the manufacturer wants to use smaller heat sinks is to save material costs. Aluminum and copper are very expensive. > You vary one of the parameters, such as heat produced, and if you want > to remain at equilibrium (i.e. constant chip temperature), you better [quoted text clipped - 3 lines] > sink, and then to the air. It doesn't necessarily lead automatically to > the conclusion that the heat sink is large. Name one high end heat sink that is small then. You cannot speed a fan up much and retain a quiet system. Its all in the heat sink - not in the fan. Unless you don't mind a loud system. Few people do though. A few years ago people had lower standards. Those noise standards are getting a little higher now that people realize they don't have to put up with that anymore. In article <replytogroup-08EE2F.19215902072007@news.lga.highwinds-media.com>, > > > > > > >Here again airflow is coming into play. Well, unless you don't > > > > > > >care [quoted text clipped - 27 lines] > > Only economically speaking to save money on materials. No, the optimum size is that which, for the given conditions, transfers the maximum heat to the cooling stream. > > > > > > > >Here again airflow is coming into play. Well, unless you don't > > > > > > > >care [quoted text clipped - 34 lines] > No, the optimum size is that which, for the given conditions, transfers > the maximum heat to the cooling stream. The maximum heat transferred is always going to come about using a large heat sink though, right? I noticed you didn't bother answering a question that I asked you twice......namely, "Name a high end heat sink that is small." Some of you think I'm talking without thinking, yet when it comes to specifics, you are silent. Name a high end heat sink that is small! Anyway, its obvious that very few if any people have ever replaced the Mini heat sink. Back to some intensive Googling. And thanks to those of you that responded with specifics. In article <replytogroup-A087CF.08451103072007@news.lga.highwinds-media.com>, > > > > > Tim, what exactly was untrue about what I said? > > > > [quoted text clipped - 12 lines] > The maximum heat transferred is always going to come about using a > large heat sink though, right? Not necessarily, as we all keep pointing out. Probably you would have to use calculus or numerical methods to calculate the optimum size. > I noticed you didn't bother answering > a question that I asked you twice......namely, "Name a high end heat > sink that is small." Of course not. Why should I know anything about specific heat sinks made by particular manufacturers? Or care, more to the point? And who says that any such heat sink bought pre-designed, is going to be the best for a particular application? I'd rather have the one designed for the situation. What these and previous threads have been trying, with little evident success, to dun into your head, are the principles involved. Another of the constraints is bound to be cost, something else you seem to poo-poo. One would make the bulk of the heat sink out of aluminium, to reduce cost and weight, and have a copper plug in it where it meets the chip. The plug itself would need to be designed, again to provide a good impedance match with the aluminium. The impedance mismatch is due to the different thermal conductivities of copper and aluminium. > In article > <replytogroup-A087CF.08451103072007@news.lga.highwinds-media.com>, [quoted text clipped - 18 lines] > Not necessarily, as we all keep pointing out. Probably you would have to > use calculus or numerical methods to calculate the optimum size. Actually, thermal calculations are similar to the ones used to calculate series resistors. IOW, really simple. 1) From the chip's data sheet, determine the "thermal resistance" from the chip (it's called the "junction" for historical reasons) to the package (called the "case") -- it's called "theta j-c", and it's expressed in degrees per watt. 2) Use the data sheet for the heat sink grease (or pad) to determine theta c-s (case to sink, again in degrees per watt). 3) Use the heat sink data sheet to determine theta s-a (sink to air, degrees per watt, and it's given for still air and for a range of flows). For a custom sink, you can easily measure theta s-a. 4) Simply *add* theta j-c, theta c-s, and theta s-a. That gives you theta j-a, the temperature difference per watt transported between the junction (the chip) and the air, for that specific heat sink, installation method, and air flow. 5) From the chip data sheet, look up the power consumed by the chip (in watts), or measure it. 6) Multiply that number by theta j-a. That gives you the actual temperature difference between the chip and the air when transporting the specified number of watts. 7) Take the maximum air temperature you expect (you *do* know where this thing is going to be used, don't you?), and add to it the temperature difference determined in (6). That tells you the chip (junction) temperature for that air temperature. 8) Use the device data sheet to determine the maximum allowable operating temperature for the chip. Compare to the number you calculated in (7). If (7) is lower, you can go with it, or you can consider a smaller heat sink, a smaller fan, or any similar combination. If the junction temperature is higher than specified, you have a different set of choices, involving a possibly reduced functional lifetime, or a better sink or fan. Or you can change the operating parameters of the device (e.g. reduce the clock rate) to reduce the amount of heat generated. -- Now you know more about thermal calculations than most of the newly-minted engineers I've worked with during my career. Isaac > > > > > > Tim, what exactly was untrue about what I said? > > > > > [quoted text clipped - 33 lines] > good impedance match with the aluminium. The impedance mismatch is due > to the different thermal conductivities of copper and aluminium. Finally the truth comes out. You're simply not familiar with today's heat sinks. See what I mean? This is typical of the lack of real world hardware experience here. Have a look at the websites of Thermaltake and Scythe, two of the most respected names in the industry. And then show me a high end heat sink that isn't large. In article <replytogroup-BB95B1.15594303072007@news.lga.highwinds-media.com>, > > > > > > > Tim, what exactly was untrue about what I said? > > > > > > [quoted text clipped - 38 lines] > heat sinks. See what I mean? This is typical of the lack of real > world hardware experience here. You really don't have a f.cking clue, do you? I know about heat sinks to the same extent that I know about how cars work. As someone with a physics degree, and from Imperial College at that, I can be relied upon to understand the basics of heat sinks. Friend Isaac obviously has a better detail knowledge of the theory, but then I never studied it from an engineering perspective, just from one of heat flow, and what heat is. Equally, I know the basic principles of how car engines work. But that doesn't mean I know how to design them. When I buy a car, I might well match it to the purpose - a small car for commuting, possibly a slightly larger one if I'm a commercial traveller. But I don't buy a Range Rover unless I'm a farmer. You give the impression of someone who's heard that you put fuel in one end of the car, and it makes the wheels turn. Then you come along and say "Gee, I've got this fluid called water, a whole lot cheaper, why don't we run the car on that instead?". That the Mac Pro's heat sinks are large is not at all interesting. They're just the end result of the design. And by the way, increasing the surface area of something within the same dimensions is easy. You might try googling for "fractal solids surface area" or some such. > In article > <replytogroup-BB95B1.15594303072007@news.lga.highwinds-media.com>, [quoted text clipped - 45 lines] > > You really don't have a clue, do you? Profanity is a sign that you've really got poor emotional control. > I know about heat sinks to the same extent that I know about how cars > work. As someone with a physics degree, and from Imperial College at > that, I can be relied upon to understand the basics of heat sinks. > Friend Isaac obviously has a better detail knowledge of the theory, but > then I never studied it from an engineering perspective, just from one > of heat flow, and what heat is. Exactly - no real world experience. > Equally, I know the basic principles of how car engines work. But that > doesn't mean I know how to design them. When I buy a car, I might well > match it to the purpose - a small car for commuting, possibly a slightly > larger one if I'm a commercial traveller. But I don't buy a Range Rover > unless I'm a farmer. That's got nothing to do with this discussion. For an educated person you sure get distracted easily. > You give the impression of someone who's heard that you put fuel in one > end of the car, and it makes the wheels turn. Then you come along and > say "Gee, I've got this fluid called water, a whole lot cheaper, why > don't we run the car on that instead?". The insults cometh. Let's veer away from specifics and start with the insult train. You're learning from Michelle. Well done. > That the Mac Pro's heat sinks are large is not at all interesting. > They're just the end result of the design. Not interesting to you because it substantiates my points. > And by the way, increasing the surface area of something within the same > dimensions is easy. You might try googling for "fractal solids surface > area" or some such. Well if it was easy, they wouldn't be always coming out LARGER models. Larger models that people have difficulty both working with and mounting. Nobody wants a larger heat sink. But that's the only way of getting top notch cooling. But you're a physicist and know all that. In article <replytogroup-9E1878.17444903072007@news.lga.highwinds-media.com>, > > You really don't have a clue, do you? > > Profanity is a sign that you've really got poor emotional control. On usenet, I see no reason to be patient with nincompoops. You've been afforded a lot of useful information and wisdom from a number of people here and haven't recognised it. > > I know about heat sinks to the same extent that I know about how cars > > work. As someone with a physics degree, and from Imperial College at [quoted text clipped - 4 lines] > > Exactly - no real world experience. This thread, and other too, have been about the PRINCIPLES that underlie how heat sinks are used. To the extent that "real world experience" comes in, I'll go with the Apple engineers. > > Equally, I know the basic principles of how car engines work. But that > > doesn't mean I know how to design them. When I buy a car, I might well [quoted text clipped - 4 lines] > That's got nothing to do with this discussion. For an educated person > you sure get distracted easily. I'm not distracted. I'm giving an analogy. You match the solution to the requirement. > > You give the impression of someone who's heard that you put fuel in one > > end of the car, and it makes the wheels turn. Then you come along and [quoted text clipped - 3 lines] > The insults cometh. Let's veer away from specifics and start with the > insult train. You're learning from Michelle. Well done. We're not talking about specifics, and never have been. > > That the Mac Pro's heat sinks are large is not at all interesting. > > They're just the end result of the design. > > Not interesting to you because it substantiates my points. Not interesting because irrelevant. > > And by the way, increasing the surface area of something within the same > > dimensions is easy. You might try googling for "fractal solids surface > > area" or some such. > > Well if it was easy, they wouldn't be always coming out LARGER models. Who is this "they" you're talking about. Real world manufacturers use what is appropriate for the job. They don't go down the aftermarket store and, to use the car analogy again, add shiny chromium bolt-on goodies to make their car look better. > Larger models that people have difficulty both working with and > mounting. Nobody wants a larger heat sink. But that's the only way > of getting top notch cooling. Not in general, as has been pointed out. And explained. > But you're a physicist and know all that. Yes that's right. But unlike you, I'm willing to be educated by the several people here who, also unlike you, actually DO have "real world experience". All of this brings up an interesting question. The Widget on my MBP says the CPU A temperature diode is 145.4 degrees F. Is this a good place to measure temps that might cause a problem and is this a good temperature? > All of this brings up an interesting question. The Widget on my > MBP says the CPU A temperature diode is 145.4 degrees F. Is this a good > place to measure temps that might cause a problem and is this a good > temperature? Intel specifies that the absolute maximum operating junction temperature for the Intel Core 2 Duo processor is 100˚ Celsius (212˚ Fahrenheit). So 145.4˚ F is just fine. <http://processorfinder.intel.com/details.aspx?sspec=sl9se#> SignatureJR In article <kurtullman-864C77.08544404072007@customer-201-125-217-207.uninet.net.mx >, > All of this brings up an interesting question. The Widget on my > MBP says the CPU A temperature diode is 145.4 degrees F. Is this a good > place to measure temps that might cause a problem and is this a good > temperature? It's the best possible place; that diode is on the same substrate with the rest of the CPU chip, and was fabricated along with the rest of it. FYI, a diode shows a "forward voltage drop" that is a predictable function of temperature. You just run a constant current through the thing, and measure the voltage across it. 145 F is about 62 C. I don't have a data sheet on that specific chip, but in general, microprocessors are perfectly happy up to about 100 C. Looks like you have plenty of margin. Isaac > In article > <kurtullman-864C77.08544404072007@customer-201-125-217-207.uninet.net.mx [quoted text clipped - 17 lines] > > Isaac Thanks. I am not sure what to make of this, but the same widget says the bottom side of the enclosure is exactly 98.6 degrees. Cue the Twilight Zone theme _grin. > Thanks. I am not sure what to make of this, but the same widget says > the bottom side of the enclosure is exactly 98.6 degrees. Cue the > Twilight Zone theme _grin. You are spending too much time with your laptop on your lap ;-) JOOI my MacBook reports 48 C (118F) diode temperature, 29C (84F) bottomside at the moment. I'm using Temperature Monitor from bresink.com Making the CPU work can jump its temperature relatively quickly - I noticed the Adobe Acrobat Reader installation took it up to 70-odd C (168-odd F) in a matter of seconds, then the fan kicked in at high speed and dropped it by 10 degrees within a very short time. The X Windows peformance tester (/usr/X11R6/bin/x11perf) makes it sound a little like a 747 winding up for takeoff. SignatureTony > In article > <kurtullman-864C77.08544404072007@customer-201-125-217-207.uninet.net.mx [quoted text clipped - 10 lines] > function of temperature. You just run a constant current through the > thing, and measure the voltage across it. Doesn't that assume that the constant current source and the voltage reference for the ADC that measures the voltage are not affected by temperature? Regards, John Byrns SignatureSurf my web pages at, http://fmamradios.com/ >> It's the best possible place; that diode is on the same substrate with >> the rest of the CPU chip, and was fabricated along with the rest of it. [quoted text clipped - 5 lines] > reference for the ADC that measures the voltage are not affected by > temperature? <pedantry> Not at all. What it does is fail to address the practical difficulties associated with trying to run a constant current through something or measure the voltage across it when temperature is neither uniform nor constant. </pedantry> Ian SignatureIan Gregory http://www.zenatode.org.uk/ian/ > >> It's the best possible place; that diode is on the same substrate with > >> the rest of the CPU chip, and was fabricated along with the rest of it. [quoted text clipped - 12 lines] > temperature is neither uniform nor constant. > </pedantry> In fact, there are no "practical difficulties" at all, using well-understood semiconductor fabrication techniques. The problem is not even slightly difficult until you get to about the third decimal place, and determining the temperature of a microprocessor to three decimals is way more than good enough to decide when to turn on a fan. Isaac > All of this brings up an interesting question. The Widget on my MBP > says the CPU A temperature diode is 145.4 degrees F. Is this a good > place to measure temps that might cause a problem and is this a good > temperature? Processor temperatures are usually measured in °C, from what I’ve read. For comparison with your processor, my Prescott is about 50°C when idle… 47°C on a good day. I don’t know how hot Core 2 Duos run, or if your system was really idle when you measured the temperature, but your 63°C may be a bit hotter than average. But as Jolly Roger points out, 63°C is perfectly healthy. > > All of this brings up an interesting question. The Widget on my MBP > > says the CPU A temperature diode is 145.4 degrees F. Is this a good [quoted text clipped - 7 lines] > system was really idle when you measured the temperature, but your 63°C > may be a bit hotter than average. My MacMini with a 1.83 GHz Intel Core Duo processor is about 50°C when idle (about 23°C room temp.), and the fan speed then is about 1500 rpm. The temp of the outgoing air is about 45°C. The highest processor temperature I've seen on this machine, after several hours of nearly 100% load, is 81°C. The fan speed was about 2500 rpm, and the temp of the outgoing air was 56°C. By the way, the noise of the fan is well below the background noise ( < 35 dBA), even when it's running at high speed. > But as Jolly Roger points out, 63°C is perfectly healthy. Yes, there is plenty of headroom left. -- > My MacMini with a 1.83 GHz Intel Core Duo processor is about 50°C > when idle (about 23°C room temp.), and the fan speed then is about [quoted text clipped - 9 lines] > > Yes, there is plenty of headroom left. Nice. I have to admit I plopped a Prescott in a case that was never meant for it. I only keep the temps that I do with my fans set to run constantly at ≥3000 RPM. It’s……… a bit noisy. :| >> All of this brings up an interesting question. The Widget on my MBP >> says the CPU A temperature diode is 145.4 degrees F. Is this a good [quoted text clipped - 9 lines] > > But as Jolly Roger points out, 63°C is perfectly healthy. 58-59°C here with a dual 1GHz G4. SignatureAndy. > > > You really don't have a clue, do you? > > [quoted text clipped - 3 lines] > afforded a lot of useful information and wisdom from a number of people > here and haven't recognised it. That's no reason to express yourself like a 12 year old. > > > I know about heat sinks to the same extent that I know about how cars > > > work. As someone with a physics degree, and from Imperial College at [quoted text clipped - 8 lines] > underlie how heat sinks are used. To the extent that "real world > experience" comes in, I'll go with the Apple engineers. Actually if you look at the title and the thread that preceded it, its precisely about real world experience. Either someone has replaced it not. Obviously no one has, or very few. > > > That the Mac Pro's heat sinks are large is not at all interesting. > > > They're just the end result of the design. > > > > Not interesting to you because it substantiates my points. > > Not interesting because irrelevant. I see you ignore all things that disagree with you. Name a top end heat sink that's small. UNLIKE the heat sinks in the Mac Pro. > > > And by the way, increasing the surface area of something within the same > > > dimensions is easy. You might try googling for "fractal solids surface [quoted text clipped - 6 lines] > store and, to use the car analogy again, add shiny chromium bolt-on > goodies to make their car look better. "They" are manufacturers of heat sinks of course. And its not about looks. Its about cooling and noise. > > Larger models that people have difficulty both working with and > > mounting. Nobody wants a larger heat sink. But that's the only way > > of getting top notch cooling. > > Not in general, as has been pointed out. And explained. Point out ONE heat sink that is top rated that is not large. > > But you're a physicist and know all that. > > Yes that's right. But unlike you, I'm willing to be educated by the > several people here who, also unlike you, actually DO have "real world > experience". But they are oddly silent when it comes to real world examples. In article <replytogroup-F4B160.20435004072007@news.lga.highwinds-media.com>, > > > > You really don't have a clue, do you? > > > [quoted text clipped - 5 lines] > > That's no reason to express yourself like a 12 year old. In your case there most certainly is. How else would I communicate with you? > > > > I know about heat sinks to the same extent that I know about how cars > > > > work. As someone with a physics degree, and from Imperial College at [quoted text clipped - 12 lines] > precisely about real world experience. Either someone has replaced it > not. Obviously no one has, or very few. This thread started off as a specific question from you, but after a few posts it moved to the principles of heat flow etc. And you haven't absorbed a single thing from all the good quality information posted here by others. > > > > That the Mac Pro's heat sinks are large is not at all interesting. > > > > They're just the end result of the design. [quoted text clipped - 5 lines] > I see you ignore all things that disagree with you. Name a top end > heat sink that's small. UNLIKE the heat sinks in the Mac Pro. Since, unlike you, I am not a subscriber to "Heat SInks Monthly", I neither know what a "top end" heat sink is in your terms, nor care. To everyone following this thread, except you, a top heat sink is one that does the job it is designed for, such as in the Mac pro and so on. The antics and toys of a few overclockers are of no interest to the millions of Mac owners whose heat sinks work just fine. > In article > <replytogroup-F4B160.20435004072007@news.lga.highwinds-media.com>, [quoted text clipped - 53 lines] > The antics and toys of a few overclockers are of no interest to the > millions of Mac owners whose heat sinks work just fine. That's because Mac owners are rarely interested in hardware excellence. And that's precisely why they are satisfied with the hardware flushed on them by Apple. >> The antics and toys of a few overclockers are of no interest to the >> millions of Mac owners whose heat sinks work just fine. > > That's because Mac owners are rarely interested in hardware > excellence. And that's precisely why they are satisfied with the > hardware flushed on them by Apple. ...or maybe it's because Mac users are more interested in getting productive work done than they are in spending every waking moment tweaking every little thing they can get their hands on, and as a result, getting nothing productive done. SignatureJR > >> The antics and toys of a few overclockers are of no interest to the > >> millions of Mac owners whose heat sinks work just fine. [quoted text clipped - 7 lines] > tweaking every little thing they can get their hands on, and as a > result, getting nothing productive done. That........is a very good point! :) |
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