What thermopad for VRM overheating? MSI 1070+P870DM.

Discussion in 'Sager and Clevo' started by poprostujakub, Sep 29, 2019.

  1. poprostujakub

    poprostujakub Notebook Consultant

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    Hi guys.
    I recently changed heatsink to T-shape, to start rising TDP of the card. Core's temperatures are pretty good (60°C with 3500RPM, 74°C with 2600RPM), but VRM is very hot. Because T-shape heatsink was designed for different layout of VRM, I added separate heatsink and fan for MOSFETs. But it doesn't work very well because of poor thermal transfer throught thermopads. Typical difference in temperatures between VRM's heatpipe and MOSFETs is 50°C, which allows VRM to heats up above 100°C. Currently I use some basic 0,5 mm thermopads.
    I considered use of graphite pads, with their thermal conductivity of 60W/mK, but I am worrying about their electrical conductivity. Anyone knows if these pads easily crumble? I don't want graphite dust between 19V and GPU's core...
    flir_20190925T172418.jpg flir_20190925T181348.jpg IMG_20190929_131434.jpg
     
  2. Meaker@Sager

    Meaker@Sager Company Representative

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    As thin and well fitting as possible.

    Thinner >> thermal pad performance.
     
    electrosoft likes this.
  3. Support.3@XOTIC PC

    Support.3@XOTIC PC Company Representative

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    I've not heard of them crumbling before. I plan on putting some in next time I have reason to open up, but hasn't come up yet.
     
  4. Meaker@Sager

    Meaker@Sager Company Representative

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    They tend to do that after being taken apart a fair few times.
     
  5. poprostujakub

    poprostujakub Notebook Consultant

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    OK, so I conducted tests with new thermopads. I bought Grizzly Carbonaut and my first thoughts - it's awesome for uneven cooling! It shows exactly in what pattern cooling is bent. And it perfectly fills this uneven gap. Now I have even lower fan speed (or GPU temperature at same fan speed).

    But for VRM it didn't help at all. It took a lot of time to insulate MOSFETs from all surrounding components and it was wasted time. It looks, that Q5D package wasn't designed for cooling from top, but completely from the bottom via PCB, because its temp closely follows temperature of the core with constant delta. Core goes 5°C up - VRM goes 5°C up. So my next step is to try to direct airflow from additional fan into between MB and MXM.
    IMG_20191004_185858.jpg IMG_20191004_185906.jpg
     
  6. Meaker@Sager

    Meaker@Sager Company Representative

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    Those pads will insulate them. Plus it looks like you could shave of some height all round. Your thinnest pad should always be 0.5mm
     
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