XPS 15 9550 temperature observations (undervolt + repaste)

Discussion in 'Dell XPS and Studio XPS' started by custom90gt, Dec 28, 2015.

  1. _sem_

    _sem_ Notebook Evangelist

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    The placement in that article is "as good as it gets", but the issue is that it doesn't solve the VRM area overheating issue. Such pads to the bottom cover actually make things worse by overheating the case and intake air if they're too conductive. If they're low-grade, they don't help enough. One reportedly successful mod by iunlock in another thread is much more involved, adds "fin" surface in the VRM area and redirects a bit of air from the vents overthere and then out through the grille. Some other thin & high-spec laptop designs make use of copper plates or heatpipes from the VRM mosfets towards the cooling fins near the fans.
     
  2. GoNz0

    GoNz0 Laptop Engineer & Online games hosting.

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    Do not bother, surely you have read it is a waste of time in 99% of cases as it overheats the case or the C/GPU no longer fully contacts the heatsink.
    Every answer you need is in this thread, no "definitive" guide as it just doesn't work out well.
    Repaste the CPU/GPU and leave it at that.
     
  3. Eason

    Eason Notebook Deity

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    Worked for me ;)
     
  4. custom90gt

    custom90gt Notebook Deity

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  5. Paul67

    Paul67 Notebook Enthusiast

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    Just undervolted for the first time ever. I have the i7 6700k with the 4k screen and my core package temps when using Prime95 hit 77c, and my Intel HD GPU temp was 61c with the GTX 960 GPU temp at 54c.

    After undervolting the CPU (and cache) by -150mv and GPU by -100mv my core package temps when using Prime95 was 62c, and my Intel HD GPU temp 55c with the GTX 960 GPU temp at 40c.

    I'm pleased with that! Admittedly though, both stress tests were only 10 minutes each, so I'll stress test it for longer to be sure.

    Then I'll do a repaste and compare.

    Thanks for sharing all this info!
     
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  6. Paul67

    Paul67 Notebook Enthusiast

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    Ok, so I did a longer stress test (about an hour) and my package core temps did rise 2 degrees to 64c.

    Now today I did a repaste using some MX-4 I had leftover here, and I'm glad I did it because when I removed the heatsink the original thermal paste was applied really thick and had typically squeezed out the sides.

    I did a trial run first and although I only applied a grain of rice size of paste that too proved slightly too much, so I was careful to apply even less the next time.

    Now however I notice my core package temps have risen to 67c (with only a degree or two difference between each core). This begs the question does MX-4 need time to bed in or could two degrees higher ambient room temperature account for the 3 degree rise in core package temps?

    Either way, 67c is still and big improvement on the 77c my initial 10 minute stress test showed.
     
  7. GoNz0

    GoNz0 Laptop Engineer & Online games hosting.

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    MX4 doesn't need bedding in but due to it being quite thick you need to press down on the heatsink with the battery disconnected after a suitable benchmark to warm the paste up so you can spread it out better.
    Performance pastes are not really developed for low pressure laptop heatsinks so some "tweaking" may be needed.
     
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  8. Paul67

    Paul67 Notebook Enthusiast

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    That makes a lot of sense Gonzo because I don't suppose there is that much pressure from those sprung metal strips holding the heatsink down. I did give it a gentle push after screwing it back down, but when the paste was cold. Heating it first before pushing it down would obviously be better at spreading the paste thinly and efficiently. Thanks for the tip!
     
  9. GoNz0

    GoNz0 Laptop Engineer & Online games hosting.

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    2 stage process m8, you did the 1st part right but you need to pop back in once things are hot. If you decide to loosen the screws to give it a bit of wiggle room you will need to keep a finger on top of each chip to stop it lifting as that can cause air bubbles.
     
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  10. Paul67

    Paul67 Notebook Enthusiast

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    Again, that make perfect sense too. Another top tip. Cheers!
     
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