MP 1,1-5,1 Hot Northbridge only on boot?

Discussion in 'Mac Pro' started by fatespawn, Jul 30, 2019.

  1. fatespawn, Jul 30, 2019
    Last edited: Jul 30, 2019

    fatespawn macrumors regular

    fatespawn

    Joined:
    Feb 22, 2009
    Location:
    Chicagoish
    #1
    I run iStatistica in the background to monitor my fans and temps. The last 3 times booting, I got messages "Northbridge temp 109C" while things are loading up. That doesn't seem reasonable since the computer is no more than 20C when I press the power button. It only happens on boot and doesn't appear the rest of the day. Has anyone else seen this strange message?
     
  2. ruslan120 macrumors 6502

    ruslan120

    Joined:
    Jul 12, 2009
    #2
    Tell it to chill? (sorry)

    Sounds like it's a (cooling) hardware failure issue.

    "Overheating of the Northbridge chip on the Mac Pro 5,1 is an endemic problem in these machines. Failure of this chip is responsible for many, if not most, main board failures. The plastic clips holding the heat-sink in place are prone to deteriorate (lifetime of about 5 years) resulting in separation of the heat-sink, rapid overheating of the Northbridge chip and failure. It seems to be planned obsolescence.

    This design fault (from the point of view of the user) can be repaired by replacing the clips with suitable metal bolts fitted with spring-loader washers. Every Mac Pro 4,1 and 5,1 owner should do this. However, the Northbridge still gets hot quickly, and races up to 80 degrees Centigrade and higher when the system is under load. "

    https://github.com/crystalidea/macs-fan-control/issues/28

    Further Evidence:
    http://www.xlr8yourmac.com/archives/jul14/071114.html
    https://discussions.apple.com/thread/7072962
    https://forums.macrumors.com/threads/mac-pro-northbridge-too-hot.468064/
     
  3. MIKX macrumors 65816

    MIKX

    Joined:
    Dec 16, 2004
    Location:
    Japan
    #3
    My 4,1>5,1 no longer " races up to 80°C " since I installed two USB powered hi CFM fans.

    There is a " temp spike" at every cold startup but nowhere near 80°C.

    I suspect that very few cMP owners thoroughly de-dust their cMPs especialy the lower Exhaust fan. . AND all of the cheesegrater holes.
     
  4. fatespawn thread starter macrumors regular

    fatespawn

    Joined:
    Feb 22, 2009
    Location:
    Chicagoish
    #4
    Thanks - and I apologize - I mixed C and F... dumb American... :)

    So, on a cold boot, my machine starts at ambient - 20-23C... But then after booting, iStatistica reports 109C almost immediately. That jump seems too much for dust or a loose heatsink - and it just started the other day.

    I blew some compressed air in and below is what I'm indicating under a Handbrake load maxing all cores.

    Anyway, I was curious if anyone had seen quick jump like that during booting.



    Screen Shot 2019-07-30 at 10.47.25 AM.png
     
  5. fatespawn thread starter macrumors regular

    fatespawn

    Joined:
    Feb 22, 2009
    Location:
    Chicagoish
    #5
    Well... this is strange... IOH Diode - that's the Northbridge, right? Notice the screenshot above doesn't show the diode, but the one below does.

    Screen Shot 2019-07-30 at 12.39.17 PM.png
     
  6. fatespawn thread starter macrumors regular

    fatespawn

    Joined:
    Feb 22, 2009
    Location:
    Chicagoish
    #6
    IMG_3440.JPG Oh... might these pieces be intricate parts of my computer? :) Can anyone identify them? When blowing compressed air, I found the spring... after a brief search, I found the plastic rivet lodged under my CPU heatsink... Thoughts?
     
  7. crjackson2134 macrumors 601

    crjackson2134

    Joined:
    Mar 6, 2013
    Location:
    Charlotte, NC
    #7
    I’m not sure if your question is serious, or rhetorical.

    That is one of the Northbridge Heatsink rivets, and it’s the reason you are seeing increased temperatures.
     
  8. DPUser macrumors 6502a

    DPUser

    Joined:
    Jan 17, 2012
    Location:
    Rancho Bohemia, California
    #8
  9. fatespawn thread starter macrumors regular

    fatespawn

    Joined:
    Feb 22, 2009
    Location:
    Chicagoish
    #9
    Yeah... kinda sarcastic/rhetorical. I found a nice video that matches that hardware precisely and it's definitely the northbridge fasteners. I have some nylon nuts/bolts coming via amazon... hopefully the other spring is still attached when I pull the processor heatsink off so I can rig up a new retention system. I have the single processor so it's totally obscured at the moment.
     
  10. DPUser macrumors 6502a

    DPUser

    Joined:
    Jan 17, 2012
    Location:
    Rancho Bohemia, California
    #10
    PS: Don't use your Mac Pro until you fix this!
     
  11. fatespawn thread starter macrumors regular

    fatespawn

    Joined:
    Feb 22, 2009
    Location:
    Chicagoish
    #11
    Yeah... it's off. When I saw 122C... I kinda figured that might be problematic. Amazon 1-day will get me what I need.
     
  12. howiest macrumors 6502

    howiest

    Joined:
    Aug 16, 2015
    Location:
    Left Coast
    #12
    I actually feel better seeing your CPU A temps under Handbrake load. I had just recently asked the same question about an alarming (to me) spike in temperature while converting a video. It would seem that the spike is normal behaviour, yet I just can't feel comfortable watching my CPU A temp rise by over 40 degrees so quickly.

    Good luck with your Northbridge rivet replacement. I have replacement rivets standing by but I would like to see the nylon bolts you've purchased for yours.
     
  13. MIKX macrumors 65816

    MIKX

    Joined:
    Dec 16, 2004
    Location:
    Japan
    #13
    Temporary but completely workable solution. I'm using it now ( permanantly ).

    Outside temp is 36°C .
    Ambient temp is 40°C .
    Northbridge chip is at 60°C.

    Japan is hot !


    You can use the spring from a broken rivet. For summer temps I prefer my own stronger spring.
    Northbridge nut & Bolt setup 02.jpg
     
  14. fatespawn thread starter macrumors regular

    fatespawn

    Joined:
    Feb 22, 2009
    Location:
    Chicagoish
    #14
    This is what I installed:
    https://www.amazon.com/gp/product/B076CLPGD3/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

    It was $14.99, but I wanted a bunch of different lengths to see how it worked. I ended up using the ones pictured. I reused both stock springs. If anyone is using springs from a ballpoint pen, I'd caution AGAINST cutting the spring for "length". It's about tension. The stock springs are much stiffer than a pen spring. I'd probably use the whole spring and a longer bolt to accommodate. It's all about keeping the appropriate contact on the die with the heatsink (I'm just guessing here...).

    IMG_3442.JPG

    Here's idle:
    Screen Shot 2019-07-31 at 3.05.37 PM.png

    Here's under a Handbrake load. The IOH diode barely moves.

    Screen Shot 2019-07-31 at 3.13.41 PM.png

    Took about 45 minutes. Most of the time was spent trying to gently remove the caked-on thermal paste on the northbridge die.

    The nice thing is the fans barely move now - even under a 100% utilization. Obviously, I replaced the thermal paste on the CPU as well. For reference, I replaced the CPU about 3 years ago with my 6-core. The thermal paste was still tacky and I had moderately good coverage. The Northbridge thermal paste was 100% dry and brittle after 10 years. So, even if folks don't have spring/rivet issues, they might want to consider a new application of thermal paste if the temperatures are starting to climb.
    --- Post Merged, Jul 31, 2019 ---
    Oh, and thanks for pointing me in the right direction everyone. I just keep putting more and more bandaids on this machine... I had a brief moment of "cool... I might actually get a new machine..." But alas... it keeps on trucking.
     
  15. howiest macrumors 6502

    howiest

    Joined:
    Aug 16, 2015
    Location:
    Left Coast
    #15
    Very informative post, thanks! Glad your machine is back to normal, and with good temps too.
     
  16. DPUser macrumors 6502a

    DPUser

    Joined:
    Jan 17, 2012
    Location:
    Rancho Bohemia, California
    #16
    Hah!

    The cheesegrater lives on!
     

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15 July 30, 2019