Can a 35W TDP CPU handle passive cooling? (1 Viewer)

zicoz

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  • September 3, 2006
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    Currently working on a new build with a i5-430m CPU. The CPU has a max TDP of 35w. Do you think it's ok to skip the fan for it?
     

    gibman

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  • October 4, 2006
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    why bother with 100% passive.

    Im running an AMD Athlon II X2 240e (energy efficient edition, approx 40watt) - Im just using the stock cooler along with speedfan installed.
    I never hear it.

    Make sure u buy a motherboard with proper speedfan support :)
    SpeedFan - Access temperature sensor in your computer

    you could configure speedfan for a target temp for cpu at 60 celsius.
    then it could sit at 0 RPMs on the cpu fan for 90% of the time.

    I highly recommend speedfan as u have guessed :)

    Just not all motherboards seem to be compatible.

    I have this one here: it has 2 fan headers that are working with speedfan from 0-100%
    gigabyte GA-MA78LMT-US2H

    /gibman
     

    Owlsroost

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    What's the thermal resistance of the heatsink (deg C/Watt), how much forced air cooling is there in the box etc ?

    (but I'd agree with Gibman - a good slow running fan is pretty much inaudible, and you won't have to worry about the CPU overheating).

    Tony
     

    zicoz

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    Wel atm I don't have either a fan nor a heatsink since the project is just getting started. I'm still in the planing stages , and one of the things I'm considdering is building the heatsink in as part of the chassis. Something that would look alittle something like this:

    heatsink concept.png

    The top drawing is from the side, the bottom drawing is from the front.

    That's just a concept scetch, I could probably put in some heat-pipes and some "rills" in it to get the heat up and away. The problem with a fan is that it adds height, something I really don't wanna do.

    I was sort of hoping that Ionic Wind would be ready by now :)
     

    funkstar

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    In some situations you might get away without a fan on the CPU itself, but you will need some kind of air movement through the case or across the heat sync.

    My main desktop has a large block passive cooler on the CPU (granted this is a Core 2 Quad) but it does have a 80mm PWM case fan near it that will drag air through the case keeping it cool. At no load the fan is completely stopped. And it's quiet even under processor load as it doesn't need to run full speed.
     

    zicoz

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    Ok thanks. Guess I'll see what I'll have to do when the parts start to arrive. Come to think of it I might use heatpipes and have a fan on the side of the motherboard aswell. Will have to see just how big it is first.
     

    Jay_UK

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    Hi there,

    Hoborg, that looks the same as my current setup. Antec case, passive CPU cooler, case fan, although I have a passive PSU and passive graphics card too.

    I am currently bulding a new fully passive case, with no fan, where the sides of the case are heatsinks.

    I will use heatpipes to transfer the heat from the CPU, GPU and NB to the heatsinks.

    J.
     

    Jelmo

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    AW: Can a 35W TDP CPU handle passive cooling?

    Sorry i have no pic at this moment, but i´m using an i3 540 + GT430. Both are placed with heatpipes to my hfx mini metal case.
    The System is without any fan. The only thing what you can hear is the 2,5" hdd. I have to look for a 100GB SSD.
    CPU never reaches 50C and the Grafic card also stays at 53C @ 1080i HDTV over some hours.
    I will take a snapshoot to show my setup
     

    funkstar

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    I am currently bulding a new fully passive case, with no fan, where the sides of the case are heatsinks.

    I will use heatpipes to transfer the heat from the CPU, GPU and NB to the heatsinks.

    J.
    I have one of these for my main HTPC - Kustom PCs mCubed HFX Chassis Silver / Black (Bare)

    A guy was selling them for about half that on eBay a few years ago. They are about 17KG of aluminium and a complete pain in the arse to work with :)

    Good concept, and they work well, just as far as modern cases are concerned, they are very poorly designed with regards to fitting and removing components and cable management.
     

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