High fan speeds during video conversion

Discussion in 'Mac Pro' started by raymanster, Feb 4, 2017.

  1. raymanster macrumors 6502

    raymanster

    Joined:
    Feb 13, 2008
    Location:
    UK
    #1
    Hi all, on my dual processor 4,1 (firmware update, upgraded dual cpu x5677, 64 GB RAM) I used MakeMKV to convert one of my blu-rays to mkv format. I then used Handbrake to encode that 24 GB to a smaller mkv.

    It all works ok, it's just the fan speeds seem to ramp up a lot during conversion. My boosta and boostb go to well over 4000 rpm. Exhaust and Intake also climb to around 2000+ rpm. The thing sounds like a vacuum cleaner! I guess they are doing their job as both cpus sit approx around the 58 - 65 degree C (136 - 149 F) mark during conversion.

    Compared to my single CPU 4,1 (firmware update, upgraded to x5670, 32 GB RAM) converting the same file it's a lot quieter. Boosta hovers around 856 rpm, exhaust and intake at 600 rpm. CPU temperature is higher though at around 74 degrees C (165 F).

    So can anyone please tell me are the high RPMs during video conversion normal on my dual processor 4,1? During idle or low cpu usage everything is fine and fans seem to run normally. I just find it odd they run at such a high RPM compared to my single processor 4,1.

    (I have Macsfan control on both Mac Pros and all settings are set to Auto.)
     
  2. JronMasteR macrumors 6502

    JronMasteR

    Joined:
    May 4, 2011
    Location:
    Switzerland
    #2
    I have higher TDP Cpu's in mine and my fans run much slower when under full load, even if they hit 80°C.
    Maybe it is another component that causes these high fan speeds.
    What temps do you get on your northbridge chip when converting video?
     
  3. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #3
    May be you can post some screen captures of MacsFanControl, which may help us to understand more (all temperature and fan speed readings). Prefer one capture during idle and other one under stress.
     
  4. raymanster thread starter macrumors 6502

    raymanster

    Joined:
    Feb 13, 2008
    Location:
    UK
    #4
    Thanks for the input guys.

    So far I have re-install OS X El Cap just to be sure as the OS X install I was using came from my single cpu 2009. Unfortunately that didn't help and still the same high rpm under load.

    I can't seem to see the northbridge temp listed, will double check also try and get screen shots. Right now I'm running Apple hardware (full long test) to see if it picks up anything.
     
  5. orph macrumors 6502a

    Joined:
    Dec 12, 2005
    Location:
    UK
    #5
  6. raymanster thread starter macrumors 6502

    raymanster

    Joined:
    Feb 13, 2008
    Location:
    UK
    #6
    I'll give it a go thanks. I'm starting to suspect it might be the heat sinks unevenly tightened or improper thermal paste application. I've ordered some and will take things apart later this week.
     
  7. raymanster thread starter macrumors 6502

    raymanster

    Joined:
    Feb 13, 2008
    Location:
    UK
    #7
    Looks like I've fixed my own problem!

    I think I put too much thermal paste and also wasn't careful enough to tighten down the heatsinks evenly. So I re-did all that and the fans no longer scream when cpus are running at or close to 100%. :)
     
  8. pastrychef macrumors 601

    pastrychef

    Joined:
    Sep 15, 2006
    Location:
    New York City, NY
  9. raymanster thread starter macrumors 6502

    raymanster

    Joined:
    Feb 13, 2008
    Location:
    UK
    #9
    I will do, cheers. I have Macs Fan Control installed so I can cool things a bit more.
     

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