Cooler Northbridge on The Mac Pro 5,1 Dual CPU

Discussion in 'Mac Pro' started by drolson, Mar 15, 2019 at 9:36 PM.

  1. drolson macrumors newbie

    Joined:
    Sep 17, 2015
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    WI
    #1
    get Northbridge temp down to 120 F ( 49c ) direct the airflow over the Northbridge Heatsink Mac Pro 5,1 Temps.png Northbridge Heatsink.jpg
     
  2. thornslack macrumors 6502

    Joined:
    Nov 16, 2013
    #2
    That’s innovative. Just be careful it doesn’t fall off, if the metal is conductive it could create a short potentially.
     
  3. adam9c1 macrumors 68000

    adam9c1

    Joined:
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    Chicagoland
    #3
    Do you have "before" and "after" photos?
    how is the noise?
    --- Post Merged, Mar 15, 2019 at 11:02 PM ---
    If this does work and extends the life of the cMP then maybe using the super sticky hvac silver tape is the better route. Sure not as clean looking.
     
  4. MIKX, Mar 16, 2019 at 1:23 AM
    Last edited: Mar 16, 2019 at 7:28 PM

    MIKX macrumors 6502a

    MIKX

    Joined:
    Dec 16, 2004
    Location:
    Japan
    #4
    Even though I realise that the Northbridge is rated for high temps I've always felt that the it runs just too hot in cMP 4,1 & 5,1.
    Many MR members have reported 75°C which cannot be good for the heatsink rivets.

    I have a temporary solution that I'm testing but bear in mind this is just a proof of concept.
    Without the fan ( below ) the NB was showing 75°C in Hardware Monitor 5.5. not as good as drolson's 49°C but still a 20°C reduction which can only be a good thing.
    Currently under the same previous conditions the NB has now been at a constant 55°C for 60 minutes of normal use with the heatsink at 46°C

    1. Yesterday I found a very slim USB case fan that ouputs a nice amount of air quietly for ¥1,000 here in Japan.
    I trimmed all extraneous plastic off the fan and it sits quite nicely between the rear memory banks and the front CPU.


    Incidentally the fan's dimensions are Width = 78mm. Height = 8mm.
    01 USB lim fan.JPG

    Here it is in situ -the lower part of the fan passes air over the NB heatsink.

    02 Fan insitu.JPG

    After installing it I rigged a temporary side cover for the CPU Tray space from laminated plastic.
    03 Quick trays cover.JPG

    From tomorrow, I'm going to power the fan internally SATA-USB

    01 Nortbridge Temps.png


    =====================================================
    Another Idea I had was to remove the GPU two fans on one cable from an old MSI HD 5770.
    MSI GPU fans.JPG

    I can get a SATA to a mini-4pin GPU socket cable there just enough space for the cable to be run up and to the cmp SATA socket with the side cover closed.
    One fan can sit directly over the rear memory bank and the other much closer to the Northbridge chip & heatsink.
    Of course I'll have to rig up a jig to hold the fans in place - that won't be so difficult.
    Also, I could rig up an extension "plug in " cable for if the CU tray might have to be removed.

    NOTE : Does anyone sell authentic replacement Northbridge heatsinks with the sensor cable ?
    Please place a link to the seller & that item here. I'd be very grateful.
     
  5. h9826790 macrumors G4

    h9826790

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    Hong Kong
    #5
    I wonder if we can install a plastic board like this to achieve similar result.
    BigLittleFrank.jpg
     
  6. MIKX macrumors 6502a

    MIKX

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    Japan
    #6
    Martin, you must have been reading my mind ! That would direct a lot more air down to the heatsink AND the NB chip. . and .. it only needs to be the same width as the heatsink area directly in front of it.

    I'll try it tomorrow !


    PS : My Northbridge is now 43°C after three hours with the fan in post #1 The NB heatsink shows 35°C
     
  7. Flocarino macrumors regular

    Flocarino

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    Montreal, Canada
    #7
    A band of silver adhesive tape, carefully place would surely do the trick. Well done DROLSON;)
     
  8. drolson, Mar 16, 2019 at 11:38 AM
    Last edited: Mar 16, 2019 at 12:46 PM

    drolson thread starter macrumors newbie

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    WI
    #8
    there is no chance in a trillion it falling off would do anything, if anybody is worried about it put some tape in it, it is cheap, fast and easy, 1 1/4 inches high and start one space up from the heatsink it makes a difference, makes no noise, and with the air flow it would get sucked to the cooler if anything

    if you really want to run cool for general stuff get a single CPU tray, they are going for $100 or sometimes $50, put in a 3.46 6 core or go with a cheaper 6 core CPU, when you don't need a dual CPU change the dual CPU tray with your Single CPU tray and you will be running so quiet you won't even hear it running and so cool there will be icicles on it
     
  9. MIKX, Mar 16, 2019 at 7:08 PM
    Last edited: Mar 16, 2019 at 8:04 PM

    MIKX macrumors 6502a

    MIKX

    Joined:
    Dec 16, 2004
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    Japan
    #9
    h9826790

    I have a spare 4,1 dual CPU tray to play with but I'm pretty busy today - I'll look at this " Diverting more airflow to the Northbridge" project this coming week.
    --- Post Merged, Mar 16, 2019 at 8:03 PM ---
    Regarding my use of a 79mm x 8mm USB fan in post #4 in this thread

    I feel that there is definitely a need for more effective Northbridge cooling in view of the fact that 4,1 2009 Mac Pros in particular are now 10 years old !

    Yesterday I installed the USB fan ( cable to cMP front USB port until my SATA to USB cable arrives ).
    Since last night I kept my 4,1 cMP running YouTube video and iTunes playlists all night plus I had some large Quicktime .mov vids loopingtoo
    Now admittedly, it is still cold winter here in Japan but this morning Harware Monitor 5.5 shows Northbridge Chip at 50°C ( down from 75°C prior ) + Northbridge Sensor at 42°C.

    with USB fan DAY 2.png

    A 25°C temperature reduction for the Northbridge chip is nothing to sneeze at.

    I'm boning up on PWM cables and intend to add a fan speed controller in the SATA to USB cable chain.

    I'll also be trying out h9826790's suggestion with my spare 4,1 dual cPU tray to find the optimal design for a 'non-conductive, securely attached airflow diverting shield.

    Luckily for me my current 4,1 dual CPU tray is a refurbished one & in excellent condition . . new rivets etc. bought just last year.
     
  10. startergo macrumors 6502a

    startergo

    Joined:
    Sep 20, 2018
    #10
    All internal fans, minimum to no noise 32deg C ambient (Florida):

    upload_2019-3-17_18-0-3.png
    upload_2019-3-17_18-1-1.png
    upload_2019-3-17_18-1-47.png
     
  11. h9826790 macrumors G4

    h9826790

    Joined:
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    Hong Kong
    #11
    Thanks for the sharing, however, I personally don't think any fan base on the heatsink temperature is a good idea.

    If the heatsink is detached. The heatsink temperature will be low, so the fan won't spin up. But the diode temperature will be very high, and your setting will give it less fan to cool down.
     
  12. startergo macrumors 6502a

    startergo

    Joined:
    Sep 20, 2018
    #12
    That is true but physically the fans can only blow in the same direction. So they are generally cooling that area. So whatever lies in that area (designed by Apple) will be cooled as well. What am I doing is: I take the highest temperature and base some sensors on that temperature. If you think about, it it works.
     
  13. h9826790, Mar 17, 2019 at 3:46 PM
    Last edited: Mar 18, 2019 at 12:39 AM

    h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
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    Hong Kong
    #13
    NO, I mean when the rivet breaks. That's the most critical situation. Your fan profile won't help, but make it worst.

    MacsFanControl using "target fan speed mode" to control the fans, which will completely override ALL system protection. No matter how hot the NB chip, if the NB heatsink is cool, your fan will NOT spin up.

    I give you an example.


    1) under normal situation. NB 55C, NB heatsink 48C

    According to your setting.

    Boost A ~3000RPM, Intake and Exhaust ~1260RPM


    2) NB rivet broken. NB 130C, NB heatsink 35C

    According to your setting.

    Boosta A 5200RPM, Intake and Exhaust 600RPM (no extra cooling provide by Intake and Exhaust fans even though the NB is clearly overheating)


    3) NB rivet broken, NB 130C, NB heatsink 35C

    All fan base on NB temperature, min 50, max 60

    Boosta A 5200RPM, Intake and Exhaust 2800RPM (all fans work at max speed and hopefully can safe the NB)


    IMO, it's better to base on the actual point that you want to protect. You want to protect the NB, not the NB heatsink. Make the fans base on NB heatsink is NOT fail safe.
     
  14. startergo macrumors 6502a

    startergo

    Joined:
    Sep 20, 2018
    #14
    Ok you say base it on the diode not the heatsink. I will change that.
    --- Post Merged, Mar 17, 2019 at 5:38 PM ---
    upload_2019-3-17_20-38-27.png
     
  15. octoviaa macrumors member

    Joined:
    Oct 19, 2013
    #15
    @startergo,

    Is it recommended to run the fan at such high speed?

    Your IOH and CPU temps are definitely impressive, however the Fans (Intake, Exhaust and BOOSTA) are running at much higher speed (2X or more than designed idle, if I'm not mistaken) which will definitely shorten the lifespan of the fan itself.

    To my knowledge, for many people (including me) the temp @ 75C idle is expected.

    So if 75C is considered 'safe', aiming for below 60C would be kind of overkill (un-required, though the NB chip will be very happy :)).

    I experiment using iStat to cool the NB chip a little bit by increasing both intake and exhaust to ~630 and it did reduce by 2-3C (become: 73-72C) while increasing to 700rpm will lower the temp further by 3-4C to 70-71C. I settle to use the 630rpm as with 700rpm the boosters (A & B) will increase to 1200rpm, while with 630, the boosters stays at 1170.

    I'm aiming for a balance approach to get longer life span of the NB without compromising too much on other components of the system unnecessarily.

    Thanks
     

    Attached Files:

  16. startergo macrumors 6502a

    startergo

    Joined:
    Sep 20, 2018
    #16
    How much is the price of the fan in comparison to the price of the baseboard? And the inconvenience of replacing one?
    --- Post Merged, Mar 17, 2019 at 6:54 PM ---
    or the CPU board?
     
  17. MIKX macrumors 6502a

    MIKX

    Joined:
    Dec 16, 2004
    Location:
    Japan
    #17
    With the USB fan ( post#4 ) my Northbridge chip has not risen above 54°C. in a normal non-stressed situation.

    Bearing in mind that the ambient case temp is 23°C and outside in my garden ( in Japan ) it is 11°C I still expect my Northbridge to run much, much cooler this summer which peaks at 39°C~40°Ç where I'm situated.

    The USB fan currently is a little noisy but I am making a rigid jig that will suspend the fan without it touching any of the tray components which is what is causing the current noise.

    02 Fan insitu.JPG

    If I run the USB fan suspended - touching nothing - outside the case it is virtually silent.

    I have not changed any of the cMP installed fan's speeds as I want to see just how effective the USB fan is.

    NOTE : I am on the lookout for a smaller, silent USB fan for the RAM behind CPU B.

    During this project I have surmised that the Northbridge chip contributes an enormous amount of 'difficult to dissipate & remove' heat which in turn contributes to weakening of the NB heatsink rivets.
     
  18. h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #18
    Don't set the Exhaust, but only intake. Then the Booster won't have higher idle RPM.

    There is a specific minimum ratio between Exhaust fan and Booster fan. iStat use "minimum fan speed" to control the fans, which will not manually override this setting (for info, MacsFanControl use "target fan speed", which will override this setting). When you increase the Exhaust RPM, the Booster RPM will also be increased.

    And IMO, it's better to keep positive pressure inside the case anyway (high intake than exhaust), otherwise, the dust will try to leak into the case via all the gaps. When intake > Exhaust, positive pressure will push the air out of the case via all the gaps, which also better for graphic card cooling (especially if the graphic card is open fan type).

    I believe this is the reason why Apple make the Exhaust fan is linked to all Intake and Booster fans. So, that when Exhaust spin up, Intake + Booster will also spin up, which make sure always has positive pressure inside the case.
     
  19. MIKX macrumors 6502a

    MIKX

    Joined:
    Dec 16, 2004
    Location:
    Japan
    #19
    drolson

    I tried your method without the USB fan but after 2 hours with room temp @17°C and cMP ambient @24°C the best I got was 54° for the Northbridge chip.

    I then removed the silver adhesive tape ( your mod ) , replaced the USB fan but this time two extra steps.

    1, I stress-taped the fan in place to reduce vibration, ergo fan noise.

    2. I put a 3 cm band of tape on rear of CPU A heatsink towards the rear RAM modules but aligned so that airflow from the top of the USB fan is deflected DOWN towards the NB heatsink.

    For the past two hours the Northbridge has been on a steady 50°C. fan is near silent now.

    Just ran Unigine Valley at HIGH +antialiasing X2, the NB topped out at 54°C. but after Valley quickly returned to 50°C

    I will be powering the USB fan from an empty onboard SATA male to USB female to USB fan cable male.
    With the side cover closed there is just enough room for the USB fan cable to run up to the upper case compartment for attachment to the SATA socket.

    Bear in mind that my tests are proof of concept at best.

    Lots of refinements to come but thus far; positive & consistent results.

    18 March 6-55 pm.png
     
  20. octoviaa macrumors member

    Joined:
    Oct 19, 2013
    #20
    Thank you @h9826790 , I leave the exhaust to default and the boosters are not increasing.
     
  21. MIKX macrumors 6502a

    MIKX

    Joined:
    Dec 16, 2004
    Location:
    Japan
    #21
    ( This morning. Mar. 18th 2019 )
    LEft the 4,1>5,1 with the USB fan aimed at the Northbridge all night with a bunch of apps running.
    Room temp = 15°C. Fan is virtually silent.
    USB Fan Northbridge March 19th 7-13 am.png

    Seems to be working satisfactorily.


    Thermaltake have a mini USB fan with fan speed adjustment dial. Looking into that for the future.
    --- Post Merged, Mar 18, 2019 at 4:01 PM ---
    WOW ! Now at 7:58 am the NB is at 48°C !


    USB Fan Northbridge March 19th 7-58 am.png
     

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