Mac Pro 4,1 Northbridge plastic to screw - need answer quick

Discussion in 'Mac Pro' started by adam9c1, Dec 11, 2013.

  1. adam9c1, Dec 11, 2013
    Last edited: Dec 11, 2013

    adam9c1 macrumors 65816

    adam9c1

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    #1
    Hi.
    I picked up a 4,1 used and I noticed something was loose inside.
    The seller tells me he replaced the Northbridge mount from plastic to a metal screw.

    What are the acceptable temperatures at idle and at load?
    I'm thinking I would run geekbench burn in test.

    Is this acceptable? Will I see problems down the road? Is there a heatsink on the bottom of the CPU tray? I did a quick search last night and there are a few threads of these little black pieces breaking off and difficulty of finding replacement units.
    Do you think something had to be drilled out?
    What prompted me to contact seller is the fact I heard something loose. I'm afraid the little spring is loose somewhere waiting for a short.

    The computer looks very good, it does have a slight bend to one of the handles, but other than that is nice. What's good is it's dual 2.66 which is a little boost from the base dual 2.66
    I looked now on ebay and do not see many 8 core 4,1 at all.
     
  2. azentropy macrumors 68000

    azentropy

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    Surprise
    #2
    I really don't know, probably will know more here in the next few days. I have the same model but am getting ready to swap out the CPU's this weekend so I'll have it apart.

    What are you using for temps? I can take some readings using same if you want to compare.
     
  3. adam9c1 thread starter macrumors 65816

    adam9c1

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    #3
    I have a iStat Menus 14 day trial.

    I don't know what temps are good.
    Also what temps I need to look at?
    There are several to decipher. I don't have the tower with me but it's like 4 diff temps for CPU and then more for the chipset....
     
  4. Studio K, Dec 11, 2013
    Last edited: Dec 11, 2013

    Studio K macrumors 6502

    Studio K

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    #4
    In iStat, the Northbridge is IOH Diode.

    Mine is at 62C most of the time. This seems to be 'normal', though some report lower.

    The northbridge heatsink is underneath the CPU heatsink. It is secured in place by 2 plastic screws with springs on them. Some have complained of a missing or broken plastic screw on 2009 Mac Pros. This can result in much higher Northbridge chip temperatures (in the 120s Celcius, as I recall).
     
  5. branana macrumors member

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  6. adam9c1 thread starter macrumors 65816

    adam9c1

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    #6
    After running Geekbench burn in for 15 hours or so
    IOH Heatsink 110
    IOHTDIODE 172

    Are these numbers good?
     
  7. azentropy macrumors 68000

    azentropy

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    #7
    Just ran Geekbench, just for 30 minutes, and get

    142
    166
     
  8. patrickbarnes macrumors regular

    Joined:
    Sep 24, 2012
    #8
    Yeah... that screw is either broken or missing on *a lot* of 2009 MPs (mine included).

    I couldn't get mine to boot recently (just a red light on the CPU tray). Turned out there was close to zero thermal paste on both CPUs and that screw was missing.

    The missing screw causes the heatsink to not make proper contact with the CPU, which causes overheating. I had to buy a bunch of things (Arctic Silver, desolver, wipes, etc) and fix it all myself -- cost $25 from Amazon. An Apple authorized center wanted $500 to replace the screw and fix it.

    The 2009 MPs are not built well. They have a lot of issues (fan noise, bad grounding of USB ports, etc, etc). But mine's still going until the nMP is out. :)
     
  9. adam9c1 thread starter macrumors 65816

    adam9c1

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    #9
    Are the numbers I provided good?
    IE proper working conditions?
    I stopped the burn in, and moment later checked temp with istat menus
     
  10. Studio K macrumors 6502

    Studio K

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    #10
    ARe these temps Fahrenheit or Celsius?

    If Celsius, I would be frightened.

    I've never done a Geekbench burn-in. Is that a feature on the paid version?

    By the way, my IOH Tdiode is presently 54C (idling). It's late-Fall, so the room temperature is lower. The 62C is the Mid-Summer Northbridge temp.
     
  11. adam9c1 thread starter macrumors 65816

    adam9c1

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    #11
    My temps were in F. In a cool basement. Probably 68-69 ambient temp.

    ----------

    110 f - 44 c
    172 f - 77 c
     
  12. Studio K macrumors 6502

    Studio K

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    #12
    Then these don't seem alarming to me. Not for a stress-test. Some people with the missing screw/loose heatsink were reporting 128C (presumably idle temp).

    What is your IOH Tdiode temperature (according to iStat) when not stress-testing?
     
  13. adam9c1 thread starter macrumors 65816

    adam9c1

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    #13
    I installed my old HD running ML
    ISTAT MENUS shows the following:
    NorthBridge 180 F
    NorthBridge heatsink 118 F

    I am downloading Mavericks and will install on another HD and compare.
     
  14. Studio K macrumors 6502

    Studio K

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    #14
    180F is 82C which is a bit higher than what I am seeing in my 4,1 when idling. I'm at 54C this evening.
     
  15. patrickbarnes macrumors regular

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    Sep 24, 2012
    #15
    This is my MacPro4,1 running fairly idle. All temps in C.

    [​IMG]
     
  16. Studio K macrumors 6502

    Studio K

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    #16
    Northbridge is quite a bit higher than what I am experiencing. Your Ambient is similar to mine (30C), and, in my case, drops the Northbridge temp a few degrees further. But even when my Ambient is hotter, the NB is never higher than 62C.

    You have dual processor model and I have single. I don't know if this makes a difference regarding NB chip temp.

    I do notice that your BOOST fans are going 1850rpms. THis is faster than normal, I believe. On Dual CPU mac pros, the fan speed should be around 1100 rpms. Do you have them set that way with SMC FanControl?

    It might be worthwhile for you to remove the heatsink and re-apply thermal compound to your CPUs. And to have a closer look at the NorthBridge heatsink and its mounting screws.
     
  17. Macsonic macrumors 65816

    Macsonic

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    #17
    May I know the clock speed of your CPUs? Is it 2.66ghz or 2.93ghz ?
     
  18. adam9c1 thread starter macrumors 65816

    adam9c1

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    #18
    Here is a screenshot of mine. It was booted from external USB. Energy set to not go to sleep. By the time I took the picture I imagine temp in the room was 60-62F. This is on zero load for about 7 hours.


    The numbers are in F. I tried to change the locale, restart but they came back same way
    Screen Shot 2013-12-12 at 3.35.33 PM.png

    this is on a 4,1 2x2.66

    I'm not 100% confident and want to ship the unit back.
     
  19. Studio K macrumors 6502

    Studio K

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    #19
    Your IOH Tdiode is the same as PatrickBarnes which is a bit higher than mine. But I am not really certain what is considered 'normal' temp range for the NorthBridge. You may still be within specification.

    If you'd like to take the temperature down, then you could use SMC FanControl to increase the INTAKE and EXHAUST fans to a higher rpm. That might get you down to the 60's (Celsius). Those 2 fans normally run at 600 rpms, but you could bring them up to 900 or 1000 and still not hear them all that much. Anything above 1100 rpms gets noticably noisy.
     
  20. Macsonic macrumors 65816

    Macsonic

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    #20
    From the above screenshot, your CPU temps, Boost and PCie Fan speed looks normal to me at idle. Try observing the temps when under normal to heavy load.
     
  21. adam9c1 thread starter macrumors 65816

    adam9c1

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    #21

    Istat menus has a way to tweak speed of fans. On the top right where in the picture it says default, I can click on that and adjust speed fans. Once adjusted it goes to custom, and then I do not see a way back. Even if I set to all to the left it stays at custom so maybe it's forced at that speed too (IE won't get faster even if it's needed).

    I have used istat long ago when it was free.
     
  22. pastrychef macrumors 601

    pastrychef

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    Sep 15, 2006
    Location:
    New York City, NY
    #22
    I don't see why replacing the plastic rivet with a metal screw would be a problem. As long as it holds the heatsink in properly, it should be fine.

    If you hear something loose floating around in the computer, I suggest you not turn it on until you find what it is and remove it.
     
  23. patrickbarnes macrumors regular

    Joined:
    Sep 24, 2012
    #23
    No fan control. I have already re-pasted both CPUs. The computer wouldn't start before I did that (red LED on CPU tray, wouldn't even show anything on screen).

    I am missing the plastic screw, but I used the heatsink to hold it down.

    These temps are normal for my machine. Before re-pasting my IOH temps would get to 160C and the machine would die. I've had it since launch. I'm not happy with the build quality, but it has lasted almost 5 years.

    Looking forward to replacing it with a nMP.
     
  24. adam9c1 thread starter macrumors 65816

    adam9c1

    Joined:
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    #24
    Are these numbers good?
    CPU A TDIODE 99
    CPU A HeatSink 93
    CPU A Relative to ProcHot 131
    CPU B TDIODE 83
    CPU B HeatSink 81
    CPU B Relative to ProcHot 146

    I don't know what the relative to prochot mean?
    In my screenshot those numbers are much higher than the other guys

    These numbers are idle for about 20h
     
  25. Studio K macrumors 6502

    Studio K

    Joined:
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    Location:
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    #25
    All of what iStat is reporting on your dual-CPU mac pro looks normal to me. Except for the IOH Tdiode which is 25C higher than mine.

    Relative to Prochot is how many degrees your CPU cores are from "Processor Hot" (sometimes called Max). It is a countdown so the higher the number the better. Stressing the CPU will cause this number to decrease as CPU core temps rise, getting closer to "Max". IStat likely sets this value at 100C (or 212F). Max would be the upper limit of INtel's reccomended acceptable temperature range. Intel does not publish what MAx is, but it's likely a bit higher than 100C.

    So why not stress your CPU a bit and let us know what the above temps are with all cores maxxed out.
     

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