PINOYDSL's Heatsink Lapping Guide

Discussion in 'PC Modifications' started by ojpd, Apr 1, 2007.

  1. ojpd

    ojpd Member

    I would still say that it does both. =p

    The temp that it blows at the HSF??? A little more than 35C since hot air from the inside of the case willl be mixing with the incoming ambient air.. Hence an increase in temp

    Ano?? Water Pipe?? Gong? lol Yeah.. To transfer/divert heat to a... Radiator that is being cooled by a fan that is blowing cool air on it... Or to a pump. Tama?

    IF the heat you're talking about is the HOT EXHAUST AIR coming from the HSF's fins as well as other components inside your PC... Then yeah..

    Why do I think so? Cool air travels below hot air.. So IN THEORY if you introduce a good amount of cool ambient air from the bottom part of a PC's case the cool air coming in can push the hot air towards the top of your case. If you have 2 strong exhaust fans located at the upper back portion of your case as well as a PSU with a bottom intake, front intake and back exhaust fans... The HOT INSIDE AIR can then be sucked out by these strong fans... This is where proper case airflow becomes a factor and this is why I mentioned proper case airflow. If you have ambient temps around 20C-25C good case airflow will help you keep steady cool air coming in while properly flushing out hot air.

    My answer doesn't answer the real question?

    Can you divert heat?... I can't with my bare hands but heat pipes will.

    5. which law of physics is used for thermal cooling?

    if you can answer these questions, then i will continue to add my reply here, until then... i will let you have the chance to study it carefully.

    I really wasn't the kind of guy who liked memorizing any laws of physics but if I had to guess I would say....

    LAW OF INTEREACTION? Every action has an equal and opposite intereaction?

    EX. If a man mates with a hot ovulating woman.. She will get pregnant and not be hot anymore.. Tama ba? LOL


    Haysss.. The stuff you explained here are more like the "exact science behind it all" OR the "what's happening under the hood".

    They are excellent and I find them very informative but I am actually aware enough to know how things work. However I am no scientist so try not to be too technical try to read between the lines.

    There are 3 things that I need to know.. So some enlightenment from science and physics again would be nice..

    1. If you're only spreading "heat" evenly throughout the heatsink then that would mean you are not actually getting rid of any of the heat since you're only spreading it evenly? Anyway 5500 RPM spreads heat faster VS 2000 RPM... And since PHYSICS has been introduced and since it is also a subject.. I'd like to add ENGLISH to my defense... Are you ready? hehe

    Given the 5500 RPM vs 2000 RPM difference in temperatures... And since HSF fan speed is indeed a factor in reducing CPU temperature.. AND if spreading the heat can reduce temperature...

    The term is "reducing temperature"... Kinda synonymous to the phrase "Cooling something down" right? Wouldnt that be a reason for us to consider "cooling it down" as another term for "spreading the heat more effectively which can yield lower temperatures???

    2. The most basic thing I could probably set as an example would be the touch test. AMD tech support recommended to me once as a last resort so even if exact values will not be found it is still a possible and accepted way of estimating temps.

    But anyway.. With a CPU at maximum load and a heatsink with a fan spinning at 1000 RPM.. The heatsink would feel really hot. If you have a hot kind of CPU... You can feel it...

    On the other hand if you have a CPU at maximum load with a heatsink fan spinning at 5800 RPM... When you touch the HSF the heat is noticeably gentle...

    Ambient temperature aside. But if you really wan't a value... Let's say we have a 20C room temp.

    Given #1 and #2 as my basis. A heatsink's fan is spreading the heat but at the same time cools it. Why? A touch test between an HSF at 2000RPM vs 5500RPM vs NO fan is reason enough.

    Anyway if #1 and #2 is not enough here's another something something... If you remove the fan from the heatsink and run a stability test.. 2 things will surely happen.

    1. The CPU temp will likely exceed and run beyound it's maximum temperature. But it will not last longer compared to a PC with a strong fan.

    2. The heatsink will get even hotter. IE... You will feel it with your hands.

    I mean.. If this is not reason enough why then would the heatsink get really hot without a fan? And vice versa with a fan?? If a fan only spreads the heat and cannot whatsoever cool down a heatsink why then would there be a difference in the temperature of a Heatsink without a fan VS with a fan... VS fan @2000rpm vs fan at 5500 rpm?

    If a fan can't cool a heatsink why does the heatsink get obviously hotter without a fan?? Also you might think that I am being pilosopo to you kuya pero bare in mind that I am not disrespecting you in any way. Peace tayo

    And fan speed matters. Seriously. :lol:
  2. primus

    primus Member

    bago ko ituloy ito, i suggest na mas mag-basa ka tungkol sa heat behavior, rather than sa mga enthusiast websites.

    may idea ka ba kung ano ang ratio para mapalamig mo ang isang 40c down to 30c? may idea ka ba kung anong temp pressure ang kailangan para ma-neutralize ang isang init?

    The temp that it blows at the HSF??? A little more than 35C since hot air from the inside of the case willl be mixing with the incoming ambient air.. Hence an increase in temp

    general question ito, walang additional temperature na involve, ang question is. ano ang exhaust temperature ng isang fan kung ang ambient temp ay 35c?

    Ano?? Water Pipe?? Gong? lol Yeah.. To transfer/divert heat to a... Radiator that is being cooled by a fan that is blowing cool air on it... Or to a pump. Tama?

    sorry.. my mistake, liquid heat pipe and ibig kong sabihin.. kung mapapalamig ng fan ang water sa radiator bakit kailangan pa ng radiator?, bakit hindi na lang itutok ang fan sa mismong engine? ano ba talaga ang silbi ng tubig na nag-cicirculate sa loob ng engine? pumili ka. 1. para ba palamigin ang engine block OR 2. para i-transport ang produced heat ng engine at palamigin sa radiator ang tubig para ma-reuse uli ng engine?

    IF the heat you're talking about is the HOT EXHAUST AIR coming from the HSF's fins as well as other components inside your PC... Then yeah..

    this is a general question again, mali ang sagot mo sa tanong ko.. ang linaw ng tanong ko, what i am asking is "can you manipulate heat.. " at hindi ko tinatanong na "can you manipulate AIR (hot or cold)". kung hindi pa rin malinaw sa iyo tanong ko, ito example, kung may isa kang metal plate ay pabagahin mo ang center nito, maari mo bang ilipat sa ibang direction ang baga ng plate na hindi nalilipat ang source ng heat?

    the HOT AIR is the by product of cpu and heatsink heat + ambient air. just to make this clear to you.

    SANA alam mo ang difference ng HEAT at ng AIR. ang tanong ko ay tungkol sa HEAT ENERGY at hindi ang AIR ENERGY (Hot or Cold), i can have a hot plate without producing a hot air, OR an air without a heat... so two different entity iyon at two different law of physics ang nag-gogovern duon.

    YES sure it does not!! :) you confuse yourself with the heat and air,

    so, is the heat pipe the only way to divert heat??yun lang ba alam mo? teka mag-search ka muna sa principle ng free convection and forced convection, ito ang dalawang pinaka base principle ng heat transfer, again don't confuse your self with this.

    :) hehehe.... basic law of physics ha? heheheh.. try something else, masyadong common yung law mo eh, madalas ko nang marinig yan eh, ito kaya... newton's law of cooling.. yan simple rin yan or yung Law of thermodynamics or enthalpy law.

    this not an exact science, pinaliwanag ko lang na maraming users (maybe including you) na mali ang understaning sa purpose ng fan sa isang heat block. again, the FAN is not use to eliminate the heat of the heat sink, the FAN is use to carry (as a conveyor) or spread the heat to the entire heat block., the only WAY you can use the fan to eliminate the heat from the heat block is by using a lower temperature as your intake,then again the fan is only an instrument to manipulate the direction of the airflow, because its the cold air that actually eliminates the heat, i.e. hindi mo mapapalamig ang isang heat block na nag-poproduce ng 50c at mag-lalagay ka ng isang fan na may intake temperature na 35c and hoping na magiging 20c ang temperature ng heat block.

    clear ako sa sinabi kong "cooling something down", and it is not synonymous for me, "colling something down" is the total elimination of the heat and you can achieve it IF you can neutralize or overcome the existing heat. i.e. a 50c thermal heat can be beaten by a -10c. so yung sabi kong to *cool it down* is correct to the context. yung "reducing temperature" eh puwedeng the temperature is concentrated on one point then you can spread or channel it to a different direction therefore you are reducing it but not completely removing it.

    how can you reduce the speed of a stopped vehicle?? parang ganon ang analogy nyan.

    Intindihin mo at basahin mong mabuti itong process ng FAN..

    pag mabilis ang velocity ng air fan (high rpm) lalakas ang air pressure, ngayon gagamitin natin ang air pressure sa isang heat block para ma-ispread natin ang heat sa ibang lugar ng heat block na hindi maka-absorb ng heat dahil sa *FREE CONVECTION* effect

    at dahil may finite temp ang thermal heat source hindi kayang marating ng thermal heat ang ibang lugar ng heat sink. kapag hindi marating ng heat ang ibang lugar ng heat sink mag-kukumpol-kumpol ang init nito sa iisang lugar lang, at pag-ganon ang nangyari iinit ng husto ang isang lugar kung saan nag-mumula ang init. eventually gagapang ang excess heat sa ibang lugar pero sa mabagal na ratio,

    sa madalit sabi, kung ang heat sink ay may kakayahang mag-absorb ng 200 celcius evenly sa buong heat sink, at kung ang cpu ay nag-poproduce ng 70c hindi mo dapat maramdaman ang mainit nito sa heatsink

    ngayon kaya malamig ang heat sink pag ginamitan ng fan ay hindi dahil sa intake air kundi dahil sa air pressure na nag-carry ng heat sa ibang lugar ng heat sink. tandaan mo, yung heat sink ay 200 celcius ang kayang i-load para maramdaman mo ang init nito at kung 70c lang ang produced heat ng cpu at kapag na-ispread out mo ang 70c thermal heat sa isang 200c capable heat sink ay hindi mo na mararamdaman ang init nito.

    isang example ay ang 30w soldering iron, subukan mong idikit ang 30w soldering iron sa isang 2x2x1 inches na makapal na bakal at tignan mo kung kayang paiinitin ng soldering iron yung buong bakal, hindi mo mapapainit yung buong bakal, ang iinit lang duon ay kung saan nakadikit ang soldering iron.

    PERO kung FREE CONVECTION lang ang way ng heat absorption ng heat sink at walang presence ng air pressure, then hindi maii-spread out ang init sa buong heat sink ng mabilis, at kung walang ambient fresh air walang mag-neutralize sa continous production ng heat ng cpu at duon mag-sisimulang uminit ang heat sink, kung free convection lang ang gamit sa heatsink, mag-iinit ang heatsink ng husto at unti-unting gagapang pero mabagal ang init sa buong heatsink.

    ito kasi ang hindi mo maintindihan tungkol sa heat sink, lahat ng heat sink block ay may rating kung ano ang thermal resistance niya, ang performance rating ay measured by c/w or k/w (celcius,kelvin), ibig sabihin, kung halimbawang may 30W kang thermal load at yung heatsink ay mag-increase ng 8c sa temperature nito, then yung heatsink ay may rating na 8c/30w = 0.2celcius per watts. and ibig sabihin nito ay gradually in every watts na mag-karoon ka ng thermal load ay may 0.2 celcius increase sa tempreture ng heat sink at kung ma-evenly spread mo iyon sa heat sink.

    isa ang ibig sabihin nuon, AMD processor generate more heat than the heatsink can absorb, also yung factor ng heat sink conductivity, resistance, air pressure i can go-on and on here... kung ipag-pipilitan mo yang touch test mo pero hindi mo alam ang principle ng heat transfer or yung simpleng heat sink principle (a real enthusiast should know this) at yung behavior ng thermal heat dissipation, walang patutunguhan itong discussion na ito, kasi yung sa iyo ay based on WHAT you FEEL, and not WHAT the law of physic tells us, eh walang mangyayari.. kahit na 10,000 RPM pa ang fan mo eh kung ang rating ng heatsink mo eh 1.5c/w, tapos ang CPU eh kayang mag-generate ang 150c, tapos samahan pa natin ng hot ambient air, eh talagang iinit yung heatsink mo. gets mo ba? puwede kong mapalamig ang AMD processor ng walang FAN kung gagamit ako ang 1 meter x 1 meter x 1 meter heat sink block tapos rated of 0.0001c/w yung heat sink.

    ang dapat mong ma-realize eh ito, ang reason kung bakit madaling uminit ang isang heat sink ay dahil sa ARE SIZE nito, kung hindi lang limited ang space ang computer case or kung saan puwedeng ilagay ang heat sink, aba! mag-kakabit ako ng pinakamalaking heat sink., ang problema kasi eh, because of the physical size of the mother board or the place where you can insert your heat sink is very limited, therefore there is not much room for a bigger heat sink, kaya nga yung ibang heat sink ay pataas and direction ng pag-kagawa para lang ma-compensate yung area, and problema kasi heat can spread faster and can dissipate heat effectively kung thin and wider ang heat sink than the thick and tall heat sink, yan ang reason kung bakit may fins/pin ang heat sink.

    have you consider the heat sink specs?? it's thermal resistance against air pressure value???

    ang sa iyo kasi eh ganito, aba! mabilis ang fan dapat malamig ang heatsink ko pero kung tanungin ka kung bakit eh hindi mo maipaliwanag, ang tendency kasi ng tao, pag ang usapan ay FAN, akala ng lahat the FAN can produce an extra colder air than the ambient temperature that sorround it.

    hindi complete ang variables mo, kumpletuhin mo for the sake of this discussion, ano ang thermal heat source temperature? ano ang continous heat production? is it increasing or decreasing?, ano ang heat sink heat absorption, ano ang value ng heat sink cold absoption? ano ang conductivity ng heat sink, ano ang velocity factor ng spreader? kasi ito ang value na kailang mo para malaman mo kung mag-tally lahat.

    hindi puwedeng ibigay mo lang sa akin eh yung ambient room, tapos speed ng fan, na-realize mo ba na ang heat sink can also be a cold sink? if the heat sink can absord heat, it is also subject to absord the opposite.

    again, you are talking here how the CPU can exceed the maximum temperature, sino nag-sabi sa iyo na ang CPU can exceed its maximum temp level? any electronic devices or component or any material HAS a FINITE operating thermal level., if it exceed that it will fail instantly, no IF's and no BUT's on this, kung yung bakal nga eh may melting point bago lumambot eh, again, you are ignoring the law of physics.

    again, you are completely ignoring the details that can affect our intellectual discussion.

    i pretty much answered this one.. read the above examples ang scenario about the air pressure, free convection, forced convection, heat sink behavior.

    have you realized that old computers particularly the XT,AT,386, 486 or early pentiums does not have a heatsink at all and some of them have the heat sink but no fans? that is because their emiited thermal heat is not high and can be neutralized by the ambient temp.

    siguro ang pinaka maigi mong gawin para mag-karoon ka ng maganda understaning sa thermal and how air can spread the heat, or how to manipulate heat, mag-search ka tungkol dito.

    no offense pero you cannot just use your touch/feel to rule over the law of physics.
  3. ojpd

    ojpd Member

    This is really going no where. A fan can cool down a heatsink. I'll stand by that.
  4. primus

    primus Member

    :) all of a sudden the law of physics do not apply to your fan and heat sink?? what kind of fan and heat sink do you have that can defy the law of physics?

    hehehe.. here's one for you..

    Newton's Law of Cooling states that the rate of change of the temperature of an object is proportional to the difference between its own temperature and the ambient temperature (i.e. the temperature of its surroundings).
  5. raldz

    raldz Member

    Please be objective when explaining your points... this thread is getting personal... I would like to enter the discussion and give my explanations regarding the laws of fluid dynamics and heat... Being an engineer, I know who is right and wrong among you guys... but I won't state my case because you guys are getting personal and egoistic... so please settle your differences or else I will lock this thread...
  6. Symantec

    Symantec Member

    oo nga....
  7. primus

    primus Member

    may objective naman ang thread, kaya lang at ang napapansin ko sa forum ay instead na tanggapin ang isang explanation lalo na at may proof or may concrete and logical explanation ang reply, at pag medyo hindi na kayang i-defend ang argument, eh lalabas na yung mga insulting words or acronyms which turns the whole thread into a flame magnet.

    To be honest, for me, this is so far a good thread because people can actually learn from it particularly correcting a wrong beliefs.

    instead of insults or anything like it, a simple admission of "yes you are right" or "yes you have a point" o kaya ay "Hey i learned new things". di ba mas magiging usefull, friendly and professional ang forum?.

    and with all due respect to you raldz, since you are a moderator, would it be more better if you moderate the thread without threatening to close it down especially if it is an interesting thread?, in an argument, a heated debate can always arise and as a moderator you should at least in the middle and vent your own reasoning based on your collected and practiced knowledge/thought without being bias to any party? napaka pointless kasi ng moderation mo if you would say "i know who is wrong or right but i won't join in because blah..blah...blah.."

    for me, being a moderator is a person whose job is not only to stop a heated argument or lock the thread. a moderator should also share hsi own knowledge to expand the information on the thread.

    again, no disrespect to you..
  8. raldz

    raldz Member

    like i said, the argument is between you guys.. both of you are making side comments that are getting personal and egoistic.. if i would air my ideas and comment that someone is wrong on this point or that point then someone will come out as an underdog.. and i don't want that to happen... i want to see a healthy debate, not a display of egos... locking this thread is my last resort if you guys can't come up on a mutual conclusion...

    and lastly.. locking this thread is not a threat.. it's a promise...
    so, better make up and lower your egos.. all of you...

    this is just a notice.. you may now return to the topic...
  9. ojpd

    ojpd Member

    I wanna make things clear and I want everybody who occassionally visits and checks this thread for updates to know that it was because of my mistake that started this little debate. This announcement is also for every future visitor who gets to read this Lapping Guide.. May you be looking for a serious guide or just a plain old 3rd or 4th reference guide. Anyway enjoy thread.

    [u[FOR THE RECORD:[/u]


    - But it's a term that only I am personally used to anyway if I say something like A 5500 FAST FAN helps cool down a CPU... I am actually talking about how a fan at 5500 rpm can help reduce cpu temp. And since I forgot that I am actually the only person in PinoyDSL who would say something like.. "At 5500 RPM it cools down the cpu better than the fan at 2000 RPM" so again IM SORRY.

    - This was probably a reason why I kept arguing with Primus but then it's all my fault since Primus wasnt really aware of what I was really trying to say so naturally if he read something like "AN HSF FAN CAN COOL DOWN my cpu temp" he would react and tell me that it was impossible since the definition of the cooldown word he is aware of is not the same "cool down biker" phrase that I was using in the forums.

    Anyway Primus I am VERY sorry for arguing with you. I have started reading up on a few of the things you tried to share with me.


    Primus explained the process of how and why an HSF Fan works. Anyway everybody can check out and read what he himself wrote in previous pages.


    And I am quite sure this is also one of the reasons why Primus got really pissed at me since he was actually explaining to me what the fan's purpose was and how it effectively spreads the heat and not cool down the HSF... AND HE IS RIGHT. I kept arguing with him bcoz I was talking about something that only I was aware of and his understanding of the term cool down is not the cool down term I kept saying.


  10. ojpd

    ojpd Member


    First of all I have not slept 3 nights in a row and tonight will be my fourth...

    So anyway I felt really guilty about arguing with one of the guys here because I too didnt really have an idea why I was insisting that my HSF Fan helps in cooling my heatsink.. Today is supposed to be my rest day but something at the back of my head just kept telling me not to go to sleep yet.. And then guess what? I remembered that I had a perfectly good reason why I said that my HSF Fan helps cool my Heatsink.

    I have a copy of most of the old posts before the arguments started.. Gonna try and put some here and try to understand and hopefully I can remember why I kept telling Primus that my heatsink fan was really helping in cooling my heatsink.

    Anyway here it goes..

    Ok so here's one "a fan can cool help cool my heatsink" remarks..

    Speaking of fans I also remember Primus saying something about the FAN.. Like regardless of FAN Speed CPU TEMP will still be constant??? Something like that... That actually made me switch PCs and go downstairs to start using my old 3500+ for the benchmarks.
    I can still have em if anybody wants to me to see..

    I also tried the naked CPU test with the 3500+ to see if it would run without an HSF even if this particular PC's place is not airconditioned.

    And then it hit me about 2 hours ago.... The only thing that I can think of right now as to why I would have kept on saying that MY HSF FAN CAN HELP COOL MY HEATSINK is because if I turn my airconditioner all the way up the temperature of both cores of my 3800X2 decreases..

    Simple Temps.

    My room's average ambient temp is around 20C-22C..

    My room's ambient temp doesnt get any higher than 22C and

    My loaded 3800X2 CPU temp is at 43C-44C

    I'm not gonna start arguing again and I dont have any plans to argue with primus or anybody else BUT I am hoping somebody can enlighten me again... I just wanna if it still not possible to say that my HSF fan helps in cooling my Heatsink?

    The side of my case has an airduct, an intake fan sucking in, airconditioned air and then blowing it directly towards the fan of the HSF.. 2 back exhaust fans and another lower front intake fan..

    Being back here in my room hiding from the heat actually helped remember why. I may have been high and in a retarded mental state last night and that kinda made me think less and talk like a person who can't back up his mouth..

    This is what I wanted to show to some people. This is also why I kept saying that my FAN can help cool down / helps cooling my heatsink...

    Room Temperature: 21C-22C


    FAN @ 3500 RPM
    My 3800X2 max core temp is 43C = closed side case + airduct fan
    My 3800X2 max core temp is 40C = open side ase + airduct fan


    FAN @ 5500 RPM

    My 3800X2 max core temp is 41C = closed side case + airduct fan
    My 3800X2 max core temp is 39C = open side ase + airduct fan


    FAN @ 5500 RPM + Deskfan Blowing directly to the CPU

    My 3800X2 max core temp is 39C = closed side case + airduct fan
    My 3800X2 max core temp is 38C = open side ase + airduct fan

    This is the reason why I kept saying that my HSF's FAN helps in cooling my heatsink... My room's average ambient temperature is 21C which is why I kept on talking but couldn't do any backing.


    I have an HSF Fan that helps cool my heatsink??
  11. primus

    primus Member

    this will not turn into a flame thread, but i will try my best to explain why you have a lower temp when you use a fan versus wihout one.

    first for your example.

    let's make your room temp a constant value i.e. doesn't decrease or increase (for the sake of argument.)

    let's also make your cpu temp a constant value. i.e. doesn't increase or decrease but continously producing a constant thermal heat.

    before we go on, let me clarify few small details here as to why the motherboard built-in thermal sensor reading IS NOT accurate.

    when we say *core* temp, are we talking about the actual source of the heat? or are we just talking about the surrounding of it. you have to realize that the *actual* thermal heat core is located on the actual surface of the CPU where the heat is coming from.. in this case the very top of the cpu, the problem is most of the thermal sensor is NOT located on the very top of the cpu where the heat is actually coming from i.e. physically touching the surface, most of the sensor are located just below it with a few millimeter distance, therefore it is subject to a surrounding ambient temperature variable.

    you also have to realize that the thermal sensor IS NOT attached to your heatsink.

    now let's go down to business (for the sake of argument, i would change few values here)

    your room ambient temp is 21c (constant), your thermal heat emitted by the heatsink is 63c, the *real core* temp of the cpu is let say 73c

    the thermal temp that surround the sensor is let say, 71c
    (you cannot get a true reading of the core temp if the sensor is not directly attached to it, therefore the surrounding of the sensor is subject to ambient variable)

    temp #1 - 64c - 21c = 43c -> the difference between the ambient and the heat sink (with side cover)
    temp #2 - 73c - 21c = 53c -> the difference between the ambient and the *real core temp*
    Temp #3 - 71c - 21c = 50c -> the difference between the ambient and the sensor
    Temp #4 - 43c - 40c = 3c -> the difference between the closed and opened side covers.

    On temp #1, whatever you do the ambient that surround the heatsink is always 43c(with cover), remember your heatsink is continously emitting a constant temp of 63c and an ambient temp of 21c.

    on your first example, there is a 3c difference between the opened and close cover, what it means is, if there's a side cover there is an increase of 3c temp from the heatsink and it continously building up, so your 63c heatsink is now continouly building up more heat to fill-up the entire case particularly if there is no exhaust, and your 43c that surround the heatsink or the entire case is no longer keeping a 43c, so your ambient inside the case is now 43c + 3c = 46c and keep raising.

    let's find out the new ambient temp, 46c - 21c = 25c -> this is now the ambient temp of the pc with a cover against the outside ambient temp, remember your outside temp is 21c only, you need to pump 4c lower to bring back your inside ambient temp to 43c or, in able to stabilize the heatsink to 63c you need to provide an ambient temp of 21c into it.

    with your given example between the 3500RPM and 5500RPM (let's get their difference temp with a side covers on)

    3500 RPM = 43c
    5500 RPM = 41c

    43c - 41c = 2c

    here, your 3500RPM can only provide 1c compared to 5500RPM in able to bring your heatsink to 63c, therefore..

    46c - 1c = 45c
    45c - 21c = 24c

    we still lack of 3c in able to stabilize the heatsink down to 63c and in able to get an inside ambient of 43c, and since the 3500RPM can only provide 1c due to its air volume that it can suck from the outside ambient temp, the fan cannot spread the heat properly because there's not enough air pressure and there's not enough ambient temperature to neutralize the heat sink.

    the point of all these is, without enough air pressure and ambient temperature, the fan cannot neutralize the heatsink to its rated load,therefore the heat will simply buildup and it creates a pressure heat in a spot without anywhere to go, unless the heat sink is neutralize to its operating load and enough air pressure, then the fan can spread the heat evenly,therefore there's no heat pressure on a particular spot.

    there are three things that happend with the process.

    1. the generated thermal heat of the cpu is being spread by the fan to the entire block (forced convection), it releases or reducing the thermal heat pressure of the center source of the heat, the heat pressure is distributed to the entire block by means of air pressure.

    2. depending on the speed of the fan, if the fan has a less air volume (a slower fan), the thermal heat will start to create a pressure point again because there's not enough air pressure to spread the heat to the entire block,

    3 if the fan is fast it can spread the heat faster and it sucks more cooler ambient air only to help neutralize the heat block, however, the heat block temperature WILL not drop lower than its surrounding ambient temperature.

    the bottom line is... the fan is more likely used as a heat conveyor that can spread the heat across the block rather than to cool down the heat sink,

    although, the fan can *cool down* the thermal heat that would always depend on the ambient temperature unless you will introduce a cooler air that is not coming from the ambient.

    bear in mind that the fan CANNOT produce its own temperature that is lower than the ambient temperature that surrounds it, the fan is an instrument to manipulate the direction of an airflow.

    For the sake of argument,

    let say we use a 8000RPM fan that is actually fast enough to suck the 4c that we need from the ambient so that we can feed it to the heat sink to stabilize it to 63c to maintain the 43c ambient.

    do you think by replacing the 8000RPM with a faster speed of 10000RPM can make a difference? do you think that the 10000RPM can suck more than 4c from the ambient temp?

    the answer is no because the of the finite temperature of the ambient stays the same, however, what a faster fan can do is to create a very turbulent airflow, hence, it spreads the heat a lot more faster and it comes to a point where the airflow does not give the thermal heat to form a pressure point.

    so if we were to apply the newton's law of cooling, it clearly states..

    that the rate of change of the temperature of an object is proportional to the difference between its own temperature and the ambient temperature (i.e. the temperature of its surroundings).

    sa madalit sabi, hindi talaga natin magagawang mapababa ang temperature ng heat-sink para maging kasing lamig ng ambient temp with the use of fan only, kasi palaging may difference sa heated object at sa ambient temp.


    if the heat sink is emitting 65c and the ambient is 21c, then there is a 44c difference, so... 44c - 21c = 23c na dapat nating habulin para maging 21c din ang temperature ng heat sink.
  12. ojpd

    ojpd Member

    Thanks for looking at my case. I will try to read through the reply tomorrow I am very sleepy na now.


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