Booster 1 fan remain > @715 rpm in iStat

Discussion in 'Mac Pro' started by GMunroe, Oct 5, 2013.

  1. GMunroe macrumors member

    Joined:
    Mar 24, 2012
    #1
    From what I understand the default speed of the booster 1 fan in a Mac Pro 5,1 should be 600 rpm. I am mentioning this due to the low "whirring" I am hearing with the mac on the desk 2 - 3 ft from my sitting position. I hear reports of these things being whisper silent. Wondering if I am having an issue. CPU temps remain @34 Celsius. The 5870 seems to run a little hot though.

    Anyhow just wondering if this normal?
     
  2. pastrychef macrumors 601

    pastrychef

    Joined:
    Sep 15, 2006
    Location:
    New York City, NY
    #2
    My Booster 1 and Booster 2 are at 1182rpm.
     

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  3. jetjaguar macrumors 68030

    jetjaguar

    Joined:
    Apr 6, 2009
    Location:
    somewhere
  4. flowrider macrumors 601

    flowrider

    Joined:
    Nov 23, 2012
    #4
    I run both Booster fans @ about 2300 RPM (using smcFanControl) because I want to keep both of my W5590s cool. The slight whir is really not that noticeable.

    Lou
     
  5. Studio K macrumors 6502

    Studio K

    Joined:
    Feb 17, 2013
    Location:
    United States
    #5
    Do you have single-processor mac pro? Or Dual?

    'Normal' speed for BOOST fan in single=856 rpms.
    'Normal' speed for BOOST fans in dual=1113 rpms each.
     
  6. DanielCoffey macrumors 65816

    DanielCoffey

    Joined:
    Nov 15, 2010
    Location:
    Edinburgh, UK
    #6
    Back when the 5,1 3.33 in my sig had an Apple 5870, one small SSD and one HDD I saw...

    PCI 800
    BoostA 856
    Exhaust 600
    Power 600
    Intake 600

    Ambient 22C

    Now, having replaced the 5870 with a 7950, adding the Rocket 640L and changing to two SSDs I still see...

    PCI 800
    BoostA 856
    Exhaust 600
    Power 600
    Intake 600

    Ambient 24C

    This is on a machine that has very recently been *thoroughly* dusted.
     
  7. GMunroe, Oct 5, 2013
    Last edited: Oct 5, 2013

    GMunroe thread starter macrumors member

    Joined:
    Mar 24, 2012
    #7
    This tells me that I am actually running cooler than most. Good to hear. My main concern is that it may be the source of the steady whir I hear as all other speeds are hovering around the defaults. Tried a radio shack meter and it read 53 db at the tower, not registering ear height at my seat. +/- 60 db is as the low as meter will go..

    If this is normal it's not something I am going to worry about. It gets drowned out when the forced air is on from the heat pump. Just reading posts about whisper quiet threw me off.
     
  8. Macsonic macrumors 65816

    Macsonic

    Joined:
    Sep 6, 2009
    Location:
    Earth
    #8
    Hi GMunroe. Your Boost fans seems normal. Their fan speed also depends much on your Ambient temp.
     
  9. Inconsequential macrumors 68000

    Joined:
    Sep 12, 2007
    #9
    If I remember correctly the ratio for the Boost fans to the Intake/Exhaust fans are as follows:

    SP: 1.425x
    DP: 1.85x


    So given that Intake/Exhaust min is 600, the min speeds are:

    SP: 855 RPM
    DP: 1110 RPM

    Give or take.
     
  10. Studio K macrumors 6502

    Studio K

    Joined:
    Feb 17, 2013
    Location:
    United States
    #10
    I was under the impression that the minimums (according to Apple's SMC firmware) were 855 for BOOST and 600 for INTAKE/EXHAUST. 1113 (or 1110) BOOST for Dual Processor.

    I've never seen iStat report any of these 3 fans on my single-processor Mac Pro spin slower than the rpm's mentioned above.
     
  11. Inconsequential macrumors 68000

    Joined:
    Sep 12, 2007
    #11
    Which is what i said?

    The boost fans are run off the intake/exhaust fans with a multiplier.
     
  12. Studio K macrumors 6502

    Studio K

    Joined:
    Feb 17, 2013
    Location:
    United States
    #12
    Yes, sorry for being repetitive.

    I just meant to emphasize that I was under the impression that the fans should not ever spin slower than the speeds that you mentioned in your post.
     

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