1 2 Previous Next 27 Replies Latest reply: Jul 28, 2009 10:23 AM by Samsara
Loa Level 4 Level 4 (1,905 points)
Hello,

It's become quite obvious to me that iTunes is causing an insane increase in CPU temperature, without causing an equivalent increase in CPU useage (CPU average stays roughly identical).

Right now with this Mac and OS, my up-to-date iTunes causes my CPU temp to go up between 15-20 degrees celcius in about 1 minute or two. Quitting iTunes results in normal temperatures after 2-3 minutes.

Can anyone tell me why???

Thanks

Message was edited by: Loa

Message was edited by: Loa

2.66 Nehalem Quad (8GB, 3TB, 120GT), MacBook (2.0), iBook dual USB, Mac OS X (10.5.7)
  • 1. Re: iTunes and unexplained CPU heat???
    The hatter Level 9 Level 9 (58,880 points)
    iTunes use to be one of the best methods for detecting marginal or faulty memory chips. Not saying it is memory but worth considering.

    And maybe iTunes just doesn't work well where hyper-threading is present.

    What are you using to get those readings?

    The only way to narrow it down would be to troubleshoot, maybe start with a stripped down Apple-only install.

    Question: did you previously have a PowerMac, and did you import anything with migration assistant?

    The iTunes forum probably is best place, and the Genius feature has been ID more than once as a culprit, try w/o.
    http://discussions.apple.com/search.jspa?objID=c153&search=Go&q=high+cpu
  • 2. Re: iTunes and unexplained CPU heat???
    Loa Level 4 Level 4 (1,905 points)
    Hello,

    Thanks for the reply. I'll recheck my own system if I get the time, but I'm far from alone with this problem: 2 of my friends experience the same thing and I also found others on a macrumors.com forum thread.

    http://forums.macrumors.com/showthread.php?t=710682

    All Nehalem Mac Pros, with varying modifications made to them (standard RAM or 3rd party, bare bones systems or with 5 HD...).

    I'm using both istatspro and SMCFan control, both reporting the same thing.

    Loa

    Message was edited by: Loa
  • 3. Re: iTunes and unexplained CPU heat???
    Samsara Level 4 Level 4 (1,320 points)
    I just launched Hardware Monitor and then iTunes, played a song and my CPUs heat raised by 20 degrees or so too. HM indicates what the highest temps should be and the temps raised in iTunes are still very well below them. It's possible that this is just another case, like I think, playing a movie in Quicktime which was on the boards before, where things you would think Apple apps would excel and be easy with, are not so at all.
    Yes, in fact I just played a movie and it happened as well, though not as high.
    I'm not worrying about it personally because as HM reports the temps don't come close to the upper limits. But maybe in a future OS, Apple will see to it that these apps don't place such a big strain on the machines.
  • 4. Re: iTunes and unexplained CPU heat???
    Loa Level 4 Level 4 (1,905 points)
    Hello,

    What is the most strange for me is that iTunes places a very very minimal strain on the CPUs. I watch the % of all my cores and they barely change when I play an MP3.

    How could the CPU get so much hotter without working harder???

    Loa
  • 5. Re: iTunes and unexplained CPU heat???
    Samsara Level 4 Level 4 (1,320 points)
    Hi Loa,

    I know, it is strange. Maybe it's like a racehorse running a race. The horse doesn't have to think all that much but it's body is going full out.
    Still, excessive heat is not something I would think would be good for our machines after awhile, but what I'm seeing so far at least is that it's being constrained far below the ranges that would be considered dangerous.
    Personally I'd like to see how PCs react in similar apps. If it's a universal thing to all computers or not.
  • 6. Re: iTunes and unexplained CPU heat???
    kaz-k Level 4 Level 4 (2,445 points)
    I just wonder if there'd be a possibility of too much thermal paste trouble like MacBook used to be.
  • 7. Re: iTunes and unexplained CPU heat???
    Loa Level 4 Level 4 (1,905 points)
    Hello,

    Re: thermal paste: why only iTunes?

    Loa
  • 8. Re: iTunes and unexplained CPU heat???
    The hatter Level 9 Level 9 (58,880 points)
    I agree with Tesselator that it seems iTunes is in need of being compiled to deal with Nehalem, which is only because of its Hyper-threading.

    And no, I don't see that happening running iTunes on Core i7 with Windows 7.
  • 9. Re: iTunes and unexplained CPU heat???
    Samsara Level 4 Level 4 (1,320 points)
    Thanks Hatter. Seems PCs are beating us at our own game, that is, music, videos, the multimedia stuff we do that Macs are supposed to excel at. Let's see what SL brings to the table, I'm becoming very curious.
  • 10. Re: iTunes and unexplained CPU heat???
    Loa Level 4 Level 4 (1,905 points)
    Hello,

    Can anyone test iTunes on SL beta?

    Thanks

    Loa
  • 11. Re: iTunes and unexplained CPU heat???
    Samsara Level 4 Level 4 (1,320 points)
    Hi Loa,

    I'm wondering if you get the same rise in temperatures when you use iTunes on your MacBook.

    In my experience iStat doesn't report the CPU temps as accurately as Hardware Monitor, it tends to inflate them by a few degrees, but it's still quite usable. HM is a really good utility to have around, I don't regret buying any of Dr. Bresinks products. http://www.bresink.com/osx/216202/details.html
  • 12. Re: iTunes and unexplained CPU heat???
    The hatter Level 9 Level 9 (58,880 points)
    I wonder what the status of ongoing beta and discussions would be. Plus, it isn't SL that is at fault, applications also have to be updated to run properly on Nehalem or to deal with HT and multi-thread processors.

    Temperature Monitor is the free version of HM and might be worth downloading.

    Everything in utilities had to be updated for Nehalem and 10.5.7+, and from forum discussions and news (like AYM) the author of TM/HM really goes extra mile, like trying to get Intel to divulge just WHAT temp will a cpu reach before it goes into self-protect mode.

    One beef I have with iTunes is I don't use or want it installing Bonjour, MobileMe and other sync services which are hogs in their own right and have been troublesome (including Apple Mail syncservices) thruout Leopard's existence.
  • 13. Re: iTunes and unexplained CPU heat???
    Samsara Level 4 Level 4 (1,320 points)
    Hardware Monitor is about 11 dollars. Two good things about it are, in it's demo form one can test it out and see if they like it, and see if their particular computers sensors are being picked up before they buy it.
    I'm playing music in iTunes now with HM open and the the temps have risen from about 52c normal to a high of 74c with iTunes. Still, HM tells me that the upper limit is 95c, so a 21 degree safety margin exists. Granted I don't like to see any rise in temps, too much of a G5 veteran to want that, but I believe the machines are well within their capacity to handle this. The fans are are hardly changing speeds at all.
  • 14. Re: iTunes and unexplained CPU heat???
    The hatter Level 9 Level 9 (58,880 points)
    Maybe you used CHUD on your G5? The latest version should have support for Nehalem and perhaps turn on/off H-T.

    http://www.versiontracker.com/dyn/moreinfo/macosx/14358

    95c is really on the edge. Even anything over 65c would have me on edge. And if I was going to use iTunes, use a modified fan settings profile.

    No reason it shouldn't stay below 45c.

    HT when you force one core to try to do double duty, and you have the 5570 cpu I think, which already has a higher wattage.

    My single 2.66 processor draws 150W momentarily on startup, but falls back to 45W most of the time, I don't do anything that really stresses the system.
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