All Work and No Play Makes a Quiet MacBook Pro

March 13th, 2006

This post is part of the MacBook Pro Complaints series. Instead of (or in addition to) linking directly to this post, consider linking to the series link, which includes a summary of all findings to date and direct links to the pertinent downloads that users may find useful. Thanks for reading!

I’m the (mostly) happy owner of a MacBook Pro (MBP). Like every other MBP owner, I’m excited and happy to have at my portable fingertips unprecedented Mac computing power. Also like every other owner, I’m slowly going insane from the now infamous “hissing/whining” processor noise.

As annoying as this noise is, it’s nothing new to me. I suffered a nearly identical noise on my Dual PowerMac G5, until I discovered through the folk wisdom of the Internet that “disabling CPU napping” would alleviate the problem. Ah – sweet silence! Since that day, I have been flagrantly wasting CPU energy on my Mac by way of the “disable napping” script that runs every time the computer boots. The script relies on extra software provided by Apple’s CHUD tools, and on the rare occasion when my computer has ended up temporarily without those tools, I’ve noticed almost immediately that my brain was once again being bored into by little audio termites.

The problem on the MacBook Pro is generating a lot of discussion on the web. I think it’s worse now because the laptop sits closer to and relatively level to your ears, while the G5 tower often rests somewhere around the corner of your desk and closer to the floor. Annoying whine from an Apple product? No problem, I’ll just pull the ol’ “disable napping” trick. Ha ha! I’m so good at this. What? The Pentium M doesn’t support napping? Sure enough, typing the magical “hwprefs cpu_nap=false” command at the command line returns the very unhelpful “nap not supported by this processor type.”

Over the past few weeks, a number of data points have emerged on the web about what may or may not cause the hissing noise, and what may or may not quell it. Among the most prominent is the observation that “using the built-in iSight” causes the noise to disappear. I tried this the way most people try it, by launching the bundled Photo Booth program. Sure enough. No more noise. But how could that be? I had a hard time believing that there was some magical link between the video circuitry and the “annoying noise” circuitry.

Spotting a link to discussions about the problem in Rentzsch‘s del.icio.us feed, I was reminded to look into the problem more carefully. Personally, though running the Photo Booth application does quiet the noise, it’s not something I feel comfortable doing with my extremely powerful, top-of-the-line Mac notebook!

I sat down at my MBP, intent on getting to the bottom of the problem. I planned to try different things and see what made the noise change or go away. But what’s this? No noise? Try as I might, I couldn’t get irritation to occur. Aha, I noticed at last. I’m plugged in. With the MBP plugged in and charging, apparently the computer doesn’t produce the noise. I was becoming more and more convinced that the problem lay in the CPUs. I disconnected the extremely cool magnetic power connector, and the noises immediately started occurring. If it’s a CPU issue, then perhaps disabling one of the cores will alleviate the problem. Yes, on my machine it certainly did. This is all consistent with the Dual G5 noise problem: when the lazy core has nothing to do, it makes a whining “I’m bored” noise.

It make sense that a video-intensive program like Photo Booth would alleviate the problem. Not because it’s using the built-in iSight, but because it’s furiously processing video data and undoubtedly making the most of that dual-core Pentium chip. Fine – but that means if I’m running Photo Booth I’m taking power away from other programs, like my compiler, that could really make better use of it. Also – the green glow of the iSight camera’s activity LED doesn’t exactly fade into the background. Isn’t there some other program that could keep the CPU just busy enough to stay quiet?

I’m not sure if there is such a program, so I made my own. It turns out that writing an extremely asinine program designed to spin the CPU endlessly does silence the problem. My program simply loops forever comparing the same byte of a string to a character value which it will never be. Pretty stupid, huh? At first I just let it take over the whole CPU, to confirm that the noise would stop, but then I got curious about how much I could yield and still keep the computer quiet. During my experiments, I added a call to usleep() and played with different settings to see at what threshold the noise would come back. In my extremely unscientific tests, the tool has to use around 8% of the (a?) CPU to keep the noise from happening. Arranging for less aggressive use of the CPU resulted in variations on the hissing noise’s rhythm and perceived pitch. I am willing to part with 8% of the CPU if I must, but is there a better way?

I remembered that this is UNIX, and one nice thing about UNIX is the “nice” function call, which sets your priority either lower or higher than the “standard priority.” Apparently nice() has been obsoleted by a newer “setpriority()” call, so if you want your code to be correct you should use that instead. I like using nice() because this is a hack, it works, and I like the way it sounds. Here is my complete “dumbcpu” command-line tool, which should silence your MBP:

   char* dummy = "blastedPentiumM";

   // Give this process the lowest possible priority
   (void) nice(20);

   // "Use" that CPU
   while (dummy[0] != 'l')
      // Give the CPU a rest. Use a lower value if it's still noisy.

For my less programming-minded readers, this is the source code to a complete command line tool that, when compiled, can be run from the Terminal application. If you’re not up for all that, just download the compiled binary, which also includes the source file. [Update: Check out the 1.1 version here, sorry no source for this one]. You should also be able to add the compiled binary to your “Login Items” in order to have the tool run (and your noise silenced) every time you log in to your account. (Update: This wasn’t true at first, but is now that I have changed the binary distribution to a simple application instead of a command-line tool).

How important is it to run this command-line tool instead of Photo Booth? To confirm my suspicions that running Photo Booth was robbing me of valuable processing time, I picked the closest project at hand and timed a clean build of it from the command line with xcodebuild. On my 1GB RAM MBP running full-bore, with annoying whining noises and all it takes almost 8 seconds exactly to complete this build from start to finish. Next I launched Photo Booth and ran the test again. This time it took almost 9 seconds. So Photo Booth is robbing me of 1 out of every 9 seconds. Unacceptable.

Running the above-linked tool quiets my MacBook Pro, yet allows compiles and any other ordinary tasks that want to harness my MBP’s power to complete at full-speed. Observing the behavior of all involved tasks with the “top” command line tool, it’s easy to see how the “dumbcpu” tool drops to nearly 0% CPU use when other, more important tasks are being run.

Does this problem suck? Yes. Does it need to be addressed by Apple before the world goes insane from humming/hissing disease? Yes. Does this little tool work around the problem in a more acceptable way than any other proposal I’ve seen? I humbly suggest that it does.

Update: Smart people like Kevin Ballard and Chris Liscio quickly observed that this tool takes up 100% of the CPU when the machine is idling, which sort of sucks. So to alleviate this, I put back a usleep() call in the while loop. On my MBP usleep(100) seems to cause about an 8% CPU usage, which is still half of what Photo Booth takes, and keeps the CPU quiet. The downloadable binary has also been updated with this change. Thanks Kevin & Chris for pointing this out.

Update 2: I notice a noise still persists when I run the tool, though it’s much less noticeable. I think it’s the “sound of one chip napping” or whatever. I suppose that altering the tool so that it spawned a thread to keep both CPUs busy might seriously silence the MBP. I’ll leave that as an exercise for the concerned reader.

80 Responses to “All Work and No Play Makes a Quiet MacBook Pro”

  1. Matt Craig Says:

    I have noticed that the whining I get is directly related to screen brightness – anything less than 100% makes mine hum. Furthermore, it seems to magically lower the brightness often (from 100%). So quite often I’ll hear it humming (say after waking from sleep), and sure enough, it’s screen brightness has somehow been lowered. Kicking it back up to 100% makes it silent. I’m curious if you can replicate this.

  2. Simone Manganelli Says:

    Interesting that this CPU napping problem persists even after a change in architecture, from IBM PowerPC G5 chips to Intel Core Duo chips. I wonder if that suggests that it’s a problem in the software caused by Apple, or if it’s just a design similarity between the G5 and the Core Duo that’s causing the problem…

    In any case, I hope this problem is resolved, but given that PowerMac G5’s have been exhibiting this issue for a long time with no fix, I’m not going to get my hopes up. (In other news, my iMac G5 2.1 GHz doesn’t seem to be afflicted by this problem, at least as far as I can tell.)

    — Simone

  3. Beau Hartshorne Says:

    I don’t have a MacBook Pro, but doesn’t all of this sound more like a power management issue? The 100% brightness trick, the fact that the whining occurs on G5s and Pentiums, it changes when you unplug it… Thoughts?

  4. Jack Lazar Says:

    So where do you type this bit of code into? and how do i get to it.
    I have been using macs for over ten years, but i have never acutally modified code or done anything like this.
    but i dont want to get extreme headaches.

  5. Matt Says:

    You could also try this program: http://www.bresink.de/osx/SystemLoad.html

    Originally designed for regulating load on PowerMac G5s to quell noise. You can set the amount of background load that it attempts to apply.

    Very cool feature: it can play a musical scale on PowerMac G5 power supplies using different CPU load patterns. Also seems to play an audible sound on some other computers.

    Caveat emptor, your mileage may vary, and all that.

  6. Daniel Jalkut Says:

    Interesting – the monitor less than 100% bright setting does seem to produce a noise on my MBP as well, though it’s a different noise (annoying in its own way. Ugh! When will the horrors cease?

    Beau: I think it’s interesting that so many of the noise issues have some relationship with the power management. But for the CPU noises I think it’s connected only in the sense that power management involves selectively ramping up and down on the utilizations of the processors.

    Jack: if you don’t have developer tools installed, the code will be useless to you. But you should be able to run the compiled command-line tool on your MBP. No code required! Just drag it to a Terminal window and hit return.

    Matt: thanks for that link. It’s a real shame that all of this time has been invested simply to try to get a quiet computer. That’s an interesting approach, though!

    As I type this I can’t help but notice that even though I’m running the quieting tool and I have my brightness set to maximum, there are still annoying noises (though much quieter) coming out the machine. Perhaps I’m just highly irritable, but silence is the one thing I miss about my old 500Mhz iBook. Guess I better get some headphones.

  7. Jack Lazar Says:

    Thank you both, I will try the terminal window and the SystemLoad program. If someone with an apple forums account could post this link on the forums, It would help many people, as I can see they many mac lovers are complaining about the MBP “whine”.

  8. Tag Says:

    Thank you so much. Because of your quietMBP program, I no longer have a splitting headache. I was wondering if there’s a way to run the program without opening the terminal. In other words, if it is possible to run the program in the background. Thanks.

  9. Strukt Says:


    Many thanks for this “fix”. It works fine on my macbook and i see this as a better solution than to open photobooth or use the mirror widget.

    Can this application somehow be run hidden?

  10. Ouiving Says:

    How about something more useful to eat up all the spare cycles like a distributed computing program. Folding@Home at this website http://folding.stanford.edu/ use spare cycles for protein folding. Maybe you’ll help find a cure for some human ailment. There is a terminal version too.

  11. Daniel Jalkut Says:

    For those of you looking for a way to run the program in the background – I would suggest doing so by simply adding the terminal executable to your “Login Items” from the Accounts pane in System Preferences. I am pretty sure this will do the trick.

    I like Ouiving’s suggestion of eating up the spare cycles by participating in a distributed computing project. If the CPU utilization is predictable and an be “nice’d” so that it backs off when other tasks need time, then it might be the perfect solution (aside from the fact that all of these solutions rob us of valuable battery life).

  12. Kimo Says:


    To run this in the background, just get the WidgetTerm terminal widget and run the program from it. Then you can switch to your Dashboard when you want to run or kill this process.

  13. Strukt Says:

    I tried to add it in the loginitems, and tick the hide box. But when logging out and logging in again the terminal screen pops up. Maybe this app could be recompiled so it to OSX looks like a application instead of an shellscript? if so, i think it would be possible to hide it in the background. Dont you?

    I might give it a try but my coding skills go as far as 10 PRINT “Hello World”. RUN. ;)

    This is not criticism, just thinking out loud :)

  14. Bob Maher Says:

    Why is it that folks insist this is a universal problem? I have no whine under any circumstance. None. Nada. Verified by almost two dozen people that I’ve asked to listen to it. I’m very perplexed with this – but not for the same reasons as most of you. I am (on certain forums) considered an idiot and a liar for claiming that I do not have this noise. And while I think you have posted the best and most reasonable text so far on the subject, it really bothers me that you said “like every other owner, I’m slowly going insane from the now infamous “hissing/whining” processor noise” – simply not a true statement, as many posts on Apple’s site demonstrates.


  15. Daniel Jalkut Says:

    Strukt: Thanks – I should be able to write a quick wrapper application for the tool that will cause it to be run from Login Items. I will even add a button to the wrapper to automatically do so. I will post an update here when I get a chance to do that.

    Bob: I really appreciate knowing that there are some MBP owners who do not suffer from this problem. Thanks for chiming in. It’s true, it was a little poetic hyperbole, but the sheer number of people who *do* suffer from this problem makes it exceedingly likely to me that you’re in the (very lucky) minority. Enjoy the silence! Wish I was in your shoes…

  16. Richard Says:


    Can you explain how to run the code from the terminal in the dashboard? Im not quite up on my unix execute skills.

  17. Oddy Says:

    Hi there!

    Couldn’t you do that with the second thread for keeping the other CPU not sleeping, or occupied? Because my G5 2×1.8 GHz makes this annoying whining sound and it’s driving me crazy… that would be lovely!


  18. Daniel Jalkut Says:

    OK I’ve updated the download, which now contains a simple application version of the tool suitable for adding to Login Items. Just launch the application and you’ll find a checkbox which will add the item to your login items for you.

    Oddy: The G5 problem is similar but on the G5 I was able to completely eliminate the noise by disabling “CPU napping.” To do this you have to download and install Apple’s CHUD tools. Once you do this you’ll find a “CPU” preference pane in which you can disable napping. There is also a command line tool “hwprefs” that comes with CHUD. I used that command line tool along with an AppleScript script, which can be added to Login Items and will automatically disable G5 napping at login time.

  19. Oddy Says:

    thank you!
    but it still doesn’t solve my issue.. it’s pretty weird.. sucks

    is there any chance your going to release the source for the “cocoa – version” of that mbpsilencer – app?

  20. Mark Says:

    Great minds think alike, well nearly. This very morning I was sat in work and again my iTunes play list finished and I heard the familiar whine. i hit dash board to start iTunes again and noticed the whine drop off, I am running menu meters, a great app people should try. And noticed that activating dash board had upped the second processor to 18%, interesting. Several days ago I had download the Apple Processor preferences pane, and had occasionally been getting annoyed enough when merely browsing the web or writing some plain text to turn off the second core to stop the noise. So I decided that it was blatantly something to do with load balancing on the two cores. I was planning to blog this myself, and even considered digging out the good ole GCC and trying my hand at some “proper programming” as I call it compared to my normal day of Web Applications development.

    I experimented empirically activating various functions like scrolling a PDF or a webpage to make the noise come and go. Just as i was finishing for the day, I gave my active bookmarks a quick glance and noticed one of my favourite sites had a new entry; MacBook Pro I noticed… so I started to read and was amused that these little bugs catch us all out at some time or another and in fact quite selfishly pleased that I wasn’t alone.

    Whilst I don’t know if your 8% is exactly right I completely agree with the theorem and was highly ammused by your trails to reach the magic number !

    What was new to me was your observation about the mains connectivity. As soon as I read it I agreed and the sound of a thousand pennies dropping could be heard over the damn whining noise. I had only subconsciously noticed that I heard the sound first thing in the morning at work, before I could be bothered plugging my baby in, and when I first got home from work, also can’t be bothered plugging her in right away. I shouted out loud, much to the surprise of my co worker “Yes he’s damn well right it is to do with that” A long explanation followed and some smug gloating from my non apple converted colleagues that Apples arn’t completely immune to snags.

    To be honest the problem isn’t bugging me out that much even when it’ there I run iTunes a lot and as such either am using enough cycles anyway to keep it happy or am simply drowning out the problem. I will however compile the code supplied, then I can pretend i’ve done some real programming ;-)

    Thanks for a very interesting read that was extremely relevant.


  21. Dan Soderholm Says:

    If running it as a login item doesn’t get it to hide in the background, you could try running it under GeekTool – that’ll run terminal commands and display them on your desktop. Or, for that matter, just run GeekTool to use up CPU cycles :) Mine keeps track of idle CPU % and core temperature in the bottom corner of the screen. My MBP should arrive this week and I bloody hope it doesn’t make this damn noise. Of course, if you run the CPU too high, your fan will go off, which is an entirely different sort of irritating noise :)

  22. AnotherGuy Says:

    Bob: Why do you keep policing any references to the MacBook whine problem if you’re not suffering it? Everywhere you go, you seem to want to jump on people for either suggesting this is a “universal” problem (even if they meant a “majority” problem, erroneously or not). As I recall, you were asked to stop commenting on the biggest “whining” thread on Apple’s forums because you kept saying it’s all in our heads or “the only whining is coming from you”, etc. I’m glad you’re not suffering from this problem, but your comments are absolutely 100% unhelpful (even in other, unrelated threads). Please go away.

    To the rest: I’m not suffering the “buzz” problem, but rather the “high-pitched whine” problem. They’re definitely two different noises. Unfortunately, the processor has absolutely nothing to do with it. Neither does using the iSight camera. Mine stops if I press on the rubber area of the hinge (the right-hand side, about an inch or two to the left of the right edge of the rubber). If I just *touch* it (no pressure), the sound disappears until I remove my fingers. If I press it with moderate force for a few seconds, the sound disappears for a minute or two, just as piercing as ever.

  23. AnotherGuy Says:

    Additionally, the whining only starts when the laptop is completely “pre-heated” — that is, it’s as hot as it normally gets after an hour or two of steady use. I just realized this pattern recently. It’s pretty consistent.

  24. Cryptonome Says:

    I been working in this issue and the most important one about the implementation of SpeedStep on the MacBook Pro, if you look into Reggie SE, the GUI version becouse the command line version has not been updated to work with the core duo, you will find interesting facts.

    What I discover by now OS X is only taking advantage of some of the states of the processor to reduce the power, the state is C2E and Hard C4E

    IA32_MISC_ENABLE Hard C4E ENABLE set to 1
    C4E Enable set to 0
    C3E Enable set to 0
    C2E Enable set to 1
    C1E Enable set to 0
    The Hard C4E is enabled when power cord is umpluged.

    But the problem for the noise is becoming because the Vc is not ajusted, that all.

    I’m making some experiments, enablind C1E and sending a halt, reduce the power requierements a lot, increasing the battery live. The problem is that Apple is not updating any more the Darwin source code for Intel and it’s difficult to work to find a solution to use SpeedStep in all their powe, instead of only one state.

    I will keep you posted about advance in this area.

    Your solution what it does is to exit the processor from C4E, and this solve the noise issue but reduce the battery life a lot.

  25. ElRhodeo Says:

    Well, but what I don’t get: Why does the mirror widget trick work even after you close the widget again?!? With 0% CPU usage?!?
    And I’d like to add that PhotoBooth takes only about 2% of CPU if you minimize it.

    By the way, isn’t it possible to write a script that opens that mirror widget everytime you boot and closes it a few seconds later?

  26. Mulling It Over Says:

    […] Update: About five minutes after dropping this post I came upon a workable fix from the Red Sweater Blog. The MBS: SystemLoad will also do in a bind. Both still tax the CPUs and ultimately cost battery life. I suspect this is why Apple has been so skittish about making promises about battery life. With the screech in full effect, the MacBook can be equivalent to the PowerBook. However, with the screech-silencing hacks in place keeping a processor awake, the battery life inevitably suffers and drops to sub-PowerBook levels. […]

  27. Ronzio sui MacBook Pro, come evitarlo Says:

    […] …alcuni consigliano di tenere aperto Photobooth: l’applicazione tiene impegnato il processore ed evita il rumore. Altri hanno deciso di creare un piccolo programmino che tenga impegnata la CPU quel tanto che basta (sembra un 8%) per evitare il ronzio. Poi c’è chi ha completamente disattivato il secondo core, con un procedimento più complesso e forse eccessivo. Per i più esperti: si fa con i CHUD tools che si trovano in Xcode. Oppure installate questa widget che, sfruttanto la iSight, tiene comunque impegnato il processore. […]

  28. Dan Simon Says:

    Well, this work great for me. I am just wondering why the mirror widget trick works as well. As it doesn’t take up any CPU cycles once quit (but still works till a full restart) it must be the power draw (as it continue drawing power, apparently a bug), rather than the CPU ‘utilization’ itself ?!

  29. Cryptonome Says:


    I did some final tests, the Kernel implementation of Apple for the core duo is a bull ***t, ok. I did a small c program that activate the C1E and send “Halt” intruction to the CPU. The noise gone… And the bettery live increase. I have to do some more test, I don’t want to broke your computers, but It’s very easy, very easy.

  30. Cryptonome Says:

    Just to clarify, the current kernel implementation, follow the old rules for PPC, but as much as I debug i was not able to find any change in the states of the CPU.

    As an example under less than 5% of CPU utilization the usual is that the CPU can run at the lowest speed and voltage, but if you maintain you MacBook Pro plugged nothing change, the kernel do nothing except than in hardware to really optimize the CPU states vs CPU utilization.

    The small program that I did, 100 lines of code, on start up activate the C1E state, and check the CPU tuilization if it’s less than 5 %, send a “Halt” intruction to the CPU, and so.

  31. Daniel Jalkut Says:

    Thanks Cryptonome, I’m excited to see this tool in action. If you want me to try it out privately before you release it please feel free to send me a copy.

  32. ralleria Says:

    Thank you Cryptonome, I hope you’ll find a reliable solution…..What I found scary is the apple’s silence
    Mirror widget works but it’s not so comfortable

  33. Zappy Says:

    Hmmm the Red Sweater Software is actually worse then Photobooth. You see while Photobooth will take around 16% of CPU Cycles when its open, if u make sure to hide it then the CPU Cycles is reduced to 2% and the noise is still blocked out while this uses around 7% at all times 5% more then Photobooth when hidden.

  34. Daniel Jalkut Says:

    Zappy: interesting choice of words in presenting that comparison. For the record, this tool is not typical of my company’s work, nor is it named after it. For future comparisons, why don’t we just call it “this tool.”

    I do find the underlying discovery interesting, and I think there’s obviously more to this whole problem than any of us (except perhaps Cryptonome?) yet understands.

  35. sjk Says:

    I think there’s obviously more to this whole problem than any of us (except perhaps Cryptonome?) yet understands.

    Including Apple, which is one possible explanation for their silence up to now.

  36. sw Says:

    For those smug Windows users who gloat over issues with Apple products:

    Windows XP has an USB2-related bug which causes extremely fast battery drains with Core Duo processors. The problem is so severe that they are going to have to patch it. It also required third parties to isolate and describe the issue before Microsoft took any notice (tomshardware.com in this instance). The patch isn’t yet available but is apparently in the works.

    Now, back to the MacBook Pro:

    My machine insists on spinning up a fan between every 10 and 30 seconds. The spin-up is ‘announced’ by an audible click, followed by a short ‘moo’-ing while the fan slowly spins up for a second and then decellerates again. Overall, the MacBook Pro is a quiet machine (I have the whine but am luckily spared from the screen hiss) and is certainly far quieter than the 17″ Sony VAIO I otherwise use. But this incessant temporary spinning up/down of the fans is also enough to drive you nuts (and the person sitting next to you!!!)

    I’m hoping that all sound issues can be fixed in software with future OS X update (Cryptonome’s comments certainly point in that direction). This would probably also apply to the fan control behaviour.

  37. Cryptonome Says:

    Hi all,

    I continued yesterday night working on this. I have to clarify that Apple did an incredible work to have the system ready in the short period of time given to do it.

    Apple base the performance vs power requierements, for this reason and the easier way to do it with out get in to clofict with other areas of the kernel is to just select the Hard C4E.

    I based my work on the excelent Windows Tool RightMark CPU Clock Utilty and the sort but usefull Intel documentation. In the CPU Clock Utility you can select the States and Two important variables the FID and the VID. The FID is the Multiplied and the VID is the core voltage of the cpu.

    On Normal ussage you can work as a little of a 6.0x multiplied and a Core Clock of 798 MHZ, Wrong first problem seen that the Core Duo only acept a minimum speed related to the minimum whr initialized, 1000 Mhz. Well you can trottle down a little bit, perhaps????.

    Playing with different convination of FID and VID, I discovered that:

    You can cancel the noise,
    You can increase the noise
    You can extend your battery life
    You can reduce your battery life
    You can make your system unstable

    The first problem is that the Kernel seen to try to check for the Hard State ever,

    I still don’t understand why we can not select the processor mode in the control panel as before, well I can understand that the software was not ready enough to allow this.

    And for your information if you disconect one core with the CHUD utilities, ok you elimate the noise because the Core Duo react disbling the HARD C4E state, your battery live become shorted.

    More on Tuesday, I hope in next weeken I have time to work on this and finish something usefull for all.

  38. Frank Says:

    hi @ all!!

    i got my MBP 3 days ago. After 2 days the whine started. I was laying with my girlfriend watchin a movie, then i started to hear that “noise”. It comes only, like with the others, when the charger is pluged out. With midget it works fine, thx god i dont have the brightness problem. I just open the mirror, close it and the noise is gone… :) i can live with that… ;) but if a update comes, or somethin else, i take it too :)

    @ cryptonome

    thx for ur help :) i hope u find somethin to kick thi s noise back to hell where it belongs hehehe

  39. Daniel Jalkut Says:

    Wow! What a response there has been to this post. I guess the issue is ripe for discussion. I feel that a lot of important comments have been made on this entry, but I don’t want the comments to stray too far into “me too” land, because we know this issues affects a lot of people, and to complicate matters, there are subtle distinctions in the ways it affects people.

    sw: I have also noticed the “moo-ing” you refer to. It sounds sort of like a hard drive trying to start and then failing. I am glad to know that I’m not the only one.

    I’m closing the comments for this post. If you have something extremely pertinent to add (like a new discovery), then please contact me privately so I can consider adding the information to the entry.

    Thanks for your interest, all!

    NOTE: There has been some interest among readers in making sure that if and when Cryptonome finishes his tool, they are notified of the availability. I’m in contact with Cryptonome off-line, and will update this page with a new comment when there is any progress in that area. I have been warned by an Apple developer that the kind of hacking Cryptonome is describing could be very dangerous if done wrong. I’m sure that’s why Cryptonome is spending so much time testing the program before releasing it.

    If you want to be sure to notice any updates, just subscribe to the RSS feed for this post’s comments. As soon as I learn anything new, I will post a new comment to this post. Thanks for reading!

  40. Red Sweater Blog - MacBook Pro Noise Update Says:

    […] Since I first wrote about the MacBook Pro CPU noise problem, some things have come into sharper focus. Unfortunately, there is still no official fix (or even acknowledgment of a problem) from Apple for the CPU noise, but there are some interesting tidbits I’ve noticed on the Apple discussion forums and elsewhere: […]

  41. Jasmine Strong Says:

    The noise you’re hearing is not coming from the CPU, it’s coming from the motherboard’s switching power supply. Because the CPU aggressively reduces its power consumption when it’s not doing anything, the load on the PSU fluctuates wildly with CPU activity. Because this is, after all, just a collection of silicon, coils, capacitors and other bits of 1960s radio equipment, there’s a little mechanical give there, and so when it’s cycling rapidly between “idle” and “checking to see if still idle” states, it whistles.

    Apple can fix this by pouring epoxy over whichever coil is whistling, most likely.

  42. Tornado Says:

    if u want to remove the strange processor sound u can do it this way:

    mkdir /backup
    sudo mv /System/Library/Extensions/IOPlatformPluginFamily.kext /b

    then reboot.

    I don’t take any responsabilities about this technique, use it at your own risk!


  43. Chris Schulz Says:

    I would like to add my observations of the MBP noises.

    The worst is the high pitched intermittent mosquito like noise.
    It starts immediately after booting up
    It can be turned off by:

    Opening Photobooth will turn the noise off. The noise will come back as soon as Photobooth is closed.

    There are two other apps that will keep the noise off even after they are closed.
    They are: Mirror (widget) & ComicLife
    There are only 3 conditions that will cause the noise to come back.
    1) turning computer off and on again 2) Opening and then Closing Photobooth 3) Opening iChat

    I can run any app (expect iChat) and the noise will stay off. iChat is the only app that can’t be run with the noise off. Launching iChat will always bring the noise back. But there is another odd thing about iChat. It takes several seconds before the noise comes back after opening iChat; where as when Photobooth is closed the sound comes back instantly.

    Has anyone noticed a different noise when the computer is sleeping. Normally it sounds like a high pitched intermittent mosquito noise. When I put it to sleep, the sound switches to a rapidly flapping noise. Almost like rapidly spinning helicopter blades.

    Both of these noises are greatly muffled when the computer is charging.

    Lastly when the brightness is not at 100% or 0% there is also a different noise. A continuous buzzing that comes from near the power button. But I can only hear this buzzing noise when the earlier described high pitched intermittent mosquito noise it turned off. The buzzing from the screen brightness is unchanged weather the computer is charging or not.

    Also, when the mosquito noise is off, I can also hear intermittent “mooo”ing from both far ends of the keyboard. I believe these are the MBP’s two fans.

    So, to conclude, I hear four distinct different noises. Is this consistent with other people?

  44. Virion Says:

    Chris: The CPU hiss, and all the little things that afect it, is consistent for me. I’m somewhat suprised that it can be temporarily disabled with the mirror widget. I have a Wk13 MBP and thought it’d be fixed by now as some had reported sucessful repair returns, but apparently not. The funny thing is, with the release of Boot Camp I was able to try Windows XP on it, the noise is non-existent in XP. XP does use both cores, and doesn’t really appear (on fresh install) to have much running when idle, the one thing though that doesn’t work right now is the iSight cam in XP. Now I’m not sure how it figures into all of this to begin with, and the cam might have nothing to do with it in the end, but I found it interesting that XP never produced the noise while idle, without the assistence of little workarounds. of course by idle I mean the cpus fluttered around 1-2% usage doing the normal background OS tasks, which seems about where OS X hovers when idling normally for me.

    This raises my hopes that this could technically be fixed by software, unless there was some fancy little fix included in the Apple Windows drivers, it would appear that the issue lies with OS X and Power Management in it, as Windows XP (plugged/unplugged and in different preformance states) doesn’t produce the noise. Of courswe there’s that wierd USB2 power drain bug, maybe that’s preventing the noise in XP? Further testign is needed.

  45. grommit Says:

    Tornado, could you elaborate further on our technique? Thanks.

  46. Daniel Jalkut Says:

    I’m pretty sure Tornado’s suggestion is not a great idea if you care at all about battery life on the machine. Even if you don’t care about battery life it might put your machine at risk of undue wear-and-tear if you disable such a critical piece of the OS’s software.

  47. GTS Says:

    The hissing on my MBP 1.86GHz comes and goes and lowering the LCD brightness does not affect it in anyway. If it wants to hiss, it will even hiss if the LCD settings are lowered to OFF. I installed Boot Camp and loaded XP Pro and my MBP is now almost silent. I also checked to see that both cores were running.

    I don’t like to use XP as my native OS, but with the irritating hissing noise, it’s getting more time running on my MBP these days.

  48. $h4g Says:

    Try this:

    -Launch Photbooth
    -Open a thumbnailed/saved picture in Photobooth
    -Hit Apple-Q

    Leaves no running process; noise is gone

  49. Angie Says:

    yep, worked for me

    My MacBook doesn’t do the whine unless I have my power unplugged.

    serial # W86121EHVJ2

  50. Mark Says:

    Tried the photobooth thumbnail quit trick from $h4g.

    IT WORKS!!!!

    But… How? Kind of worrying that something so unconnected could solve the problem. Surely once the ap is quit then it isnt using any processor overhead. How is it solving the problem? Sounds like I have toggled something at a low level but what?

    Help! Should I stop paying to beta test this machine and go swap it for something that doesn’t threaten to toast my hands, drill my ears, loose my (crawling and crashing software), ejects me from crashing aps every few minutes?

    serial W8610

    ps. Should I replace it with a later serial number machine or is that a myth?

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