Retina Macbook Pro Different Fan Speeds?

Discussion in 'MacBook Pro' started by boto, Jul 5, 2012.

  1. boto macrumors 6502

    boto

    Joined:
    Jun 4, 2012
    #1
    I know I am paranoid, but is it normal to receive fans speeds of around 2160 RPMs on the left and 2000 RPMs to the right in normal conditions, such as web browsing, email, and other minor usages? I want to clarify if my rMBP is defective or not, since I noticed classic MBPs have similar ranges. It seems I can never get both fans to rotate at the same level, it is always a 160 difference.

    .:apple:
     
  2. Acidsplat macrumors regular

    Joined:
    Aug 12, 2011
    #2
    I may be wrong, but one fan is on the CPU and the other is on the GPU. If you get the processor to start working along with the integrated graphics, it'll need to cool more cause they're on the same die. Since the dedicated GPU isn't being used, it doesn't need to cool more than it does idle.

    The left fan covers the processor, so if the processor and/or integrated Intel graphics is working, it'll need to cool more than the GPU side on the right as its not being utilized.
     
  3. boto thread starter macrumors 6502

    boto

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    Jun 4, 2012
  4. bizzle macrumors 6502a

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  5. Puevlo macrumors 6502a

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    Oct 21, 2011
    #5
    It sounds like one fan is getting far less electricity than it needs to function. I'd suggest jump starting it with some jumper cables.
     
  6. GekkePrutser macrumors 6502a

    GekkePrutser

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    Ireland
    #6
    Not exactly, they're both on the same heatpipe in the retina model, but one is closer to the CPU and one closer to the GPU so in that sense it is right. But they should share the load more evenly than the previous model.
     
  7. markp99 macrumors member

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    Jun 14, 2012
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    New Hampshire
    #8
    The RPM mismatch drives the OCD side of me CRAZY! :D
     
  8. TheMacBookPro macrumors 68020

    TheMacBookPro

    Joined:
    May 9, 2008
    #9
    You can use smcFanControl and set it so the fan speeds are synced ;)

    I'm more worried about the fact that it can't seem to read the computer's temperature though.
     
  9. VFC, Jul 6, 2012
    Last edited: Jul 6, 2012

    VFC macrumors 6502a

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    SE PA.
    #10
    Since the heatpipe on the right side is attached to both the CPU and discrete GPU, it may be possible that some of the heat from the CPU/HD4000 chip is being absorbed by the GPU chip and surrounding circuitry before it gets to the right fan-sink. Just a theory.....

    The L/R fan speed on my cMBP is evenly matched in "normal" mode. I would expect that to be the case since the two heatpipes are exactly centered between the CPU and GPU.
     
  10. Tankmaze macrumors 68000

    Tankmaze

    Joined:
    Mar 7, 2012
    #11
    Sorry for bringing up old post.

    But just got the retina mbp, coming from cmbp late 2011. and indeed the right and left fan speed is not in sync. the left side is usually higher,
    so I guess this is normal ? appreciate it if anyone can reply or confirm. thanks
     
  11. Samuelsan2001 macrumors 604

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    Oct 24, 2013
    #12
    It's deliberate to help direct air flow.
     
  12. Mnowell69 macrumors regular

    Mnowell69

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    Bedford, UK
  13. Tankmaze macrumors 68000

    Tankmaze

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    Mar 7, 2012
    #14
    Awesome, didn't know about this.

    Thanks for the confirmation, I'm glad it is normal.
     
  14. snaky69 macrumors 603

    Joined:
    Mar 14, 2008
    #15
    Yes, you are paranoid. Yes it can happen under certain circumstances. The left fan is closer to the CPU and GPU and sometimes works harder than the right one.
     
  15. hiranya47 macrumors newbie

    hiranya47

    Joined:
    May 12, 2017
    Location:
    India, at a computer.
    #16
    You are not wrong.
    --- Post Merged, May 12, 2017 ---
    Yes this is normal.
     

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