CPU - CPU Heatsink Difference

Discussion in 'MacBook Pro' started by tjb1, Dec 23, 2010.

  1. tjb1 macrumors 68000

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    #1
    Ive been noticing quite a difference in the temperatures of the two so just now I tried something. Running 4 threads of yes > /dev/null for 10 minutes now, I have a CPU temp of 202F and a CPU Heatsink temp of 128F. Thats a difference of 74F now either the heatsink is losing 74F faster than it can build it or something is wrong with the transfer between the two. Does something need done here?
     
  2. lostngone macrumors demi-god

    lostngone

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    #2
    Fans?

    Have you checked your heat sinks for dirt/blockage and RPM of your fans? Maybe one of your fans it dying.
     
  3. tjb1 thread starter macrumors 68000

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    #3
    Fans were both at ~5k, put them at 6k and CPU dropped to about 196 while the heatsink stayed at 128. Never had the logicboard out to check the heatsinks though, if I am going to remove the logicboard im probably gonna wait until I have some thermal paste first.
     
  4. alust2013 macrumors 601

    alust2013

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    #4
    I imagine you just need to reapply the paste, that's usually the cause of a large difference like that. Mine is rarely more than 10-15 degrees cooler, if that.
     
  5. tjb1 thread starter macrumors 68000

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    #5
    You think the paste would need re-done on a 2010?
     
  6. alust2013 macrumors 601

    alust2013

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    It's possible. Sometimes the application isn't that great stock, but usually is. That's the only thing I can think of that would cause that issue, as the heatsink can't lose heat faster than ones in other computers, and if it could, your computer would actually be running cooler.
     
  7. tjb1 thread starter macrumors 68000

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    #7
    I just cant believe there could be a 70F difference after 10 minutes, there is no way the fans are removing 70F that fast and not really affecting the CPU. Even at 6k rpm the CPU dropped more than the heatsink, about 10F for the cpu and 1-2 for the heatsink. What is the BEST thermal paste you can get?
     
  8. alust2013 macrumors 601

    alust2013

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    #8
    The difference is because the thermal paste isn't doing a good enough job of transferring the heat from the CPU to the heatsink. The fans are actually more likely removing most of the heat from the CPU, due to the heatsinks not being effective. When you changed the fan speed, the CPU dropped more, as it will much more readily change temperature than the heatsinks will, which is actually the principle that the heatsinks work on. Anyhow, I have heard arctic silver is supposed to be really good.

    Just for a reference, I have never seen my cpu above 175-180, even when using handbrake for 20 minutes or so. My heatsink was much closer in temperature than 70 as well.
     
  9. tjb1 thread starter macrumors 68000

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    #9
    Mine hit 205 quickly with the 4 threads of yes > /dev/null. Fans didnt even move until it hit 200.
     
  10. NickZac, Dec 24, 2010
    Last edited: Dec 24, 2010

    NickZac macrumors 68000

    NickZac

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    #10
    You're in spec as all MBP's run pretty hot. 205 isn't worrysome. I'd uninstall any software you use to control the fans as the computer is designed to do it automatically.

    Edit: your heatsink temp can be affected by numerous factors and it being much cooler is not unusual as it is designed to be cooler as it's what is dissipating the heat. Ambient room temp, what your comp is set on, other applications, humidity level, ventilation in the room, and even the barometric pressure can all have drastic affects on temp. Also, you have a beefy processor which most people agree runs hotter than the C2D MBPs. A 2010 shouldn't have a dust block or other block unless you've used your computer in a sandstorm.
     
  11. tjb1 thread starter macrumors 68000

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    #11
    I use SMCFanControl to mostly monitor the fan speed, its set at 2000rpm 99% of the time and doesnt affect the computer controlling the fans. Ive had the computer apart multiple times and there is no dust inside but it still seems like a large margin between the two.
     
  12. NickZac macrumors 68000

    NickZac

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    #12
    It is a little wide of a margin I do agree compared to most; if the CPU starts going much over 200 consistently, then yes, something is out of spec.
     

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