Radical cooling idea for the i9

Discussion in 'MacBook Pro' started by Ploki, Oct 5, 2018.

  1. Ploki macrumors 68040

    Joined:
    Jan 21, 2008
    #1
    I'm thinking of running it in clamshell!

    i thought of buying a spare lid like this:
    https://www.ebay.co.uk/itm/NEW-Appl...epid=0&hash=item1ca3382a26:g:5GIAAOSwnrJbfS5V
    (still have to check if it fits the A1990)

    then cutting a hole under CPU/GPU heatsink and install a huge sucking fan underneath to additional cool the heatsinks.

    Will that boost its performance or no?

    Or should i just drop 50$ and try it myself :D
     
  2. 1096bimu, Oct 5, 2018
    Last edited: Oct 5, 2018

    1096bimu macrumors 6502

    1096bimu

    Joined:
    Nov 7, 2017
    #2
    It will have practically zero impact on temperatures, you have a very poor understanding of how cooling works.
    fans don't do any good when you have no surface area.
    DSC00849.jpg DSC00850.jpg

    This is how you can actually boost cooling performance. I can cool my MacBook at max power even with the internal fans at idle. It's not even radical, it still works like a normal laptop.
     
  3. Ploki thread starter macrumors 68040

    Joined:
    Jan 21, 2008
    #3
    wait am i getting this right? You used thermal tape all over heatsinks, then just flipped the laptop and (presumably) thermal-taped a huge-ass heat sink on it?

    Have any before/after benchmarks?

    hm, technically i could use a smaller heat sink with active ventilation if i had a hole in the bottom and sticked it directly to the heat sinks.
    (wonder how much loss you get by double-taping and having aluminium in between)

    Do any "non-stick" thermal conductors exist? I dont want any glue residue on my heatsinks.

    This could make the i9 scream...
     
  4. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #4
    The internals are designed for a certain airflow and cutting holes may impact that. With that said, I believe someone did that in this forum and had some positive results.
     
  5. Queen6 macrumors 604

    Queen6

    Joined:
    Dec 11, 2008
    Location:
    Flying over the rainforest at dawn - Priceless
    #5
    You would need push a significant volume of air through the heatsync's for any effect, especially with the i9 as the TDP is so high. Bottom line is the cooling system is inadequate versus the thermal output of the processors. You could try to use the base plate to dissipate some heat, equally cooling a 28W CPU versus the I9 with over 100W...

    Q-6
     
  6. jrichards1408 macrumors 6502

    Joined:
    Nov 4, 2016
    #6
    I think it's best to wait next year for the complete cooling redesign
     
  7. 1096bimu, Oct 6, 2018
    Last edited: Oct 6, 2018

    1096bimu macrumors 6502

    1096bimu

    Joined:
    Nov 7, 2017
    #7
    No, I thermal coupled the heat pipe and the bottom panel with thermal pads. I can then just place a big heat sink on the bottom panel to cool it.
    With the mod alone, no extra heat sinks, when placed upside-down I get 20 degrees cooler while running games, down from almost 100 to 77 degrees.

    With the large heat sink and an external fan, the internal fans will stay at minimum speed with temps yet a few degrees lower at around 73.

    It won’t make the i9 scream because peak turbo speeds are still limited by thermal paste performance. With this setup I have here I still hit 100 when running over 4Ghz even with a bock of ice cooling the bottom panel. This indicate a thermal bottleneck with the thermal compound. You would need to change that into liquid metal for a significant boost in peak performance.
    Benchmark scores are not significantly changed, they just don’t drop at all over multiple cinebench runs. The first run is only like 20 points higher.

    It would be possible to just stick this sink directly on the heat pipe. I’m guessing you’ll get minimal improvements because the thermal resistance of the back panel is minimal over such a large surface area. Applying liquid metal would make a much bigger difference when combined with my thermal mod.

    Obviously you could go totally nuts, you can put a water block on the thermal system after applying liquid metal, but I don’t see the point because you can get a desktop computer with all 6 cores running at 5Ghz for half the cost.
     
  8. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #8
    Here's the thread where a member drilled holes. I think your plan may be a bit more ambitious but he saved himself 5 to 6c on idle. Its an old thread and he did it on an old laptop

     
  9. Ploki thread starter macrumors 68040

    Joined:
    Jan 21, 2008
    #9
    Really? And it works SO well?
    Dang, I could just cut a hole in the desk and replace it with a giant heatsink in that case. I might as well do that. Thanks for your input
     

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8 October 5, 2018