Limiting CPU usage - How

Discussion in 'macOS' started by hotshotharry, Feb 18, 2008.

  1. hotshotharry macrumors 6502

    Sep 6, 2007
    Does anyone know of a way to limit individual applications and cap their max cpu usage.

    Like say i want to restrict handbrake to 70% cpu usage max, is there an option or something?

    The reason i ask is because seeing processors temps of 70C are a bit concerning lol, i dont mind if it takes 10 mins longer :) and sometimes i work in hot areas and the cpu temp can be 60C sitting idle with fan running flat out !

  2. tYsopz macrumors member

    Nov 11, 2007
    I searched to find out this and failed, and seeing as it already was a thread on this i figured i'd bump it instead of making a new.

    I remember I could do it with the terminal, but i do not remember how.
  3. applefan69 macrumors 6502a

    Oct 9, 2007
    yeah I am concerned about heat in my macbook too... after downloading/having SMCfan running, and forcing my macbooks fan to run about 200RPM's faster then regular idle my macbook went from 56-60 celcisu idle, to 50-54 celsius at idle. Which im content with.

    BUT whenever i play games or pretty much anything process intensive, I get into 70-75 celsius. I HAVE even seen it running 80 a couple times, usually when it gets that hot i quit what im doing and let it cool down im not sure but i think i've heard the core2duo heat limit is 90 degress celsius??

    If someone can confirm that or not, but it still worries me to see my macbook running so close to the max heat.
  4. Jotaro macrumors newbie

    Jul 4, 2008
    I decreased my cpu temp with downclock via software now my laptop run at 58 / 60 degree using coolbook application.

    Hope can be useful for you.

  5. KingYaba macrumors 68040


    Aug 7, 2005
    Up the irons
  6. Consultant macrumors G5


    Jun 27, 2007

    Yup. Take out the battery would make the computer run at half the clock speed.

    You should search
    macupdate or versiontracker
  7. ayeying macrumors 601


    Dec 5, 2007
    Yay Area, CA
    Core 2 Duos have a processor temp of 100 deg C. Relax if you think 70deg C is hot. The processors in the laptops were made to handle that much heat. This isn't a desktop processor nor a desktop here. Don't sweat on the CPU being 70 deg C. Sweat when it hits 100+.
  8. m1ss1ontomars macrumors 6502

    Oct 1, 2006
    Indeed. The Core Duo and Core 2 Duo processors have a maximum junction temperature of 100 degrees Celsius. In other words, if you go over your processor will malfunction and may sustain irreversible damage.
  9. DoFoT9 macrumors P6


    Jun 11, 2007
    My CD can get to 120°C with no problems, i think the hardware emergency shutdown is somewhere around that number.

    anyone found a fix to this im very interested to fix it.

    i did find this

    which (when you use x264 and type threads=1 into the advanced options in handbrake) makes it use only 1 CPU, users of it still experienced the same heat readings and it hardly reduced the FPS at all..
  10. Matek macrumors 6502a

    Jun 6, 2007
    Like a couple have already stated - this is NOT a problem. The chip works at much higher temperatures without any problems. I assure you - you will not help your processor in ANY way by running it at 60C instead of 70C, so stop worrying about it.

    Have a cold one and cool yourself off instead ;).
  11. Gallomimia macrumors newbie

    Jun 30, 2010
    My computer usually hovers around 80-82 when being pushed. It's a mbp13" 7.1 2.66ghz c2d with a m320 graphics chip (also the northbridge) I just started a port upgrade outdated and it's hit 85. While gaming and using the gpu heavily, if I hit 83-85 I will begin to see relics and texture errors in the graphics. It's a set of white squares roughly a half inch wide that flicker and get in the way of enjoying the game. If it's a shooter, usually no problems. If it's a text based interface such as EVE online, it gets rather hard to read important information on screen. In any event restarting the game after letting it cool down is the way to go.

    I've looked at cpulimit as a solution. It looks like there's an attempt to port it to mac but I haven't found the result of this. (It does its job simply by sending signals to the target process)
  12. Mr. Retrofire macrumors 603

    Mr. Retrofire

    Mar 2, 2010
    On a Quad-Core add this to the advanced parameters (HandBrake):
    or this
    on a Dual-Core machine.

    HandBrake (HB) uses a lot of SSE2/SSE4 instructions, which saturate the memory I/O system (even on SB-machines), so that virtual cores (HT) are not able to improve the performance of the x264 encoder in HB. That means, you should use
    for maximum performance and
    :threads=(NumberOfPhysicalCPUCores / 2) + 1
    for lower temperatures (RAM & CPU semiconductors). +1 is for the I/O thread.

    Some other tricks:
    Use the "renice" command (Terminal) to give HB a lower priority:
    sudo renice 19 PID
    "PID" is the process id, which you can find via Activity Monitor or via the
    command in a Terminal window.

    You can reduce the CPU usage of some apps via the Terminal, if you know you do not need them (a web browser for example):
    kill -SIGSTOP PID
    reduces the CPU usage of the process with the process id "PID" to zero.
    kill -SIGCONT PID
    resumes the process with the process id "PID".
  13. GGJstudios, Feb 6, 2012
    Last edited: Feb 6, 2012

    GGJstudios macrumors Westmere


    May 16, 2008
    Note the date of this thread. Gallomimia seems to like necroposting.
  14. militantm1nd, Sep 6, 2012
    Last edited: Sep 6, 2012

    militantm1nd macrumors newbie

    Sep 6, 2012
    On a soundwave in Canada
    Hi so I don't know where to input the advanced options to control HandBrake's CPU usage... is it in the advanced x264 option string? If it is, do I have to re-input the ":threads" command per source or can I plug it in once and have it apply to all?

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