voidcom
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Q: Mac Pro 2008 (3,2 GHz) CPU gasket

Hello,

 

The computer is only going to be used for playing games and I'm planning to remove the two E5462 CPU's and put in a X5482 (E0 stepping), which I can get for 40 bucks. I think the system will just run with 1 CPU as well, right? I read that the 3,2 GHz model uses a gasket between the CPU and heat sink, as well as liquid metal instead of the usual grease.

 

Does anyone know what the gasket is made of and how it looks in greater detail, and what exactly is its purpose? I was unable to find a good picture on the web. I thought I could perhaps cut out something using 0,5 mm copper sheet. Any other ideas, other than purchasing an original gasket?

 

Is the liquid metal grease, e.g. Collaborate Lab Liquid Cooing Ultra and gasket really necessary? Or is it that at the time there was simply nothing better available and more modern non-conductive or air corrosive grease would do the same?

 

Thanks!

Mac Pro, OS X Mavericks (10.9.5), 8-core (upgraded)

Posted on Oct 16, 2016 2:01 PM

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Q: Mac Pro 2008 (3,2 GHz) CPU gasket

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  • by lllaass,

    lllaass lllaass Oct 16, 2016 2:38 PM in response to voidcom
    Level 10 (190,755 points)
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    Oct 16, 2016 2:38 PM in response to voidcom

    This upgrade makes not discussion of doing anything special to installing 5482s in a 2008 MP.

    http://www.xlr8yourmac.com/systems/2008_MacPro_Dual_X5482s.htm

  • by voidcom,

    voidcom voidcom Oct 16, 2016 5:09 PM in response to lllaass
    Level 1 (13 points)
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    Oct 16, 2016 5:09 PM in response to lllaass

    Thanks for responding. I was also reading some other material discussing the use of grease vs. liquid metal and apparently liquid metal does help to provide some better cooling, although only a few degrees that may not be worth it considering the disadvantages of using liquid metal.

     

    I was wondering though why Apple decided to use a gasket and liquid metal for the 3,2 GHz model. Does the gasket perhaps prevent that anything runs over contacts or because the liquid metal gets damaged when in contact with air? Maybe it works with some other stuff, but just for fun I would like to experiment with liquid metal. It would help however if I would know more details about the gasket.

  • by lllaass,

    lllaass lllaass Oct 17, 2016 1:38 AM in response to voidcom
    Level 10 (190,755 points)
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    Oct 17, 2016 1:38 AM in response to voidcom

    I would use a good thermal compound like Arctic Silver

    http://www.newegg.com/Product/Product.aspx?Item=N82E16835100007

  • by voidcom,

    voidcom voidcom Oct 18, 2016 5:24 PM in response to lllaass
    Level 1 (13 points)
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    Oct 18, 2016 5:24 PM in response to lllaass

    I already bought Collaborate Lab Liquid Cooing Ultra. I've seen some report from 2006, comparing CLL Pro with Artic Silver 5 showing that under load there can be as much as 8 degree Celsius less using CLL Pro under CPU "load".


    Meanwhile I found an interesting picture of a CPU, which may shows the gasket surrounded by Kryptox grease. I think the grease is supposed to seal the CPU and heatsink. I have not seen anyone else doing this and I wonder.


    Any ideas?


    Screen Shot 2016-10-19 at 2.12.24 AM.jpg

  • by voidcom,

    voidcom voidcom Oct 19, 2016 8:27 PM in response to voidcom
    Level 1 (13 points)
    Desktops
    Oct 19, 2016 8:27 PM in response to voidcom

    Here's a link with more pictures:

     

    http://forums.macrumors.com/threads/remove-liquid-metal-thermal-paste-on-2008-3- 2ghz.1914250/

     

    It looks to me that more liquid metal is required in order to fill the gap between the CPU and heatsink, compared to what needs to be applied without the gasket.

     

    So perhaps I could cut out some square gasket from 0.5 mm or less copper sheet. Some of the videos that demonstrate how to apply Collaborate Lab Liquid however do not use a CPU gasket and do not seal it with Krytox grease, and instead advice to provide only a very thin layer of the liquid metal. The stuff that Apple used apparently goes bad after 30 min. exposure to air. Does the same happen to Collaborate Lab Liquid and why do they not advice to use a gasket?

  • by lllaass,

    lllaass lllaass Oct 20, 2016 1:18 AM in response to voidcom
    Level 10 (190,755 points)
    Apple Watch
    Oct 20, 2016 1:18 AM in response to voidcom

    Interesting link.

    If the compound yo are using does not say yo need a spacer/gasket I would not try to make a gasket.

    It appears that the Apple compound is really a liquid and not a paste like other compounds.

    I think with a gasket, the "paste" yo use may result in too thick of a paste layer and make heat transfer worse.

  • by voidcom,

    voidcom voidcom Oct 20, 2016 8:59 PM in response to lllaass
    Level 1 (13 points)
    Desktops
    Oct 20, 2016 8:59 PM in response to lllaass

    Good point, but the same argument may also apply to what Apple used. CLL Pro/Ultra and the stuff Apple uses looks the same, both are liquid. Wouldn't be a thin layer best in any case? What I have not seen anywhere is that CCL reacts to air, or like Apple has a 30 minute limit. Perhaps that could have been a reason for sealing the stuff with Krytox.

     

    I've sent the manufacturer or distributor of CLL Ultra an email, questioning the matter of using a cpu gasket and sealing the heatsink, but have not received a response yet.