10.8 heat issues Mountain Lion MBP

Discussion in 'OS X Mountain Lion (10.8)' started by chrisby, Sep 7, 2012.

  1. chrisby macrumors newbie

    Jul 26, 2011
    I performed a clean install of 10.8 which was kept up to date as of yesterday at 10.8.1. Battery life was terrible as it was with lion, but now the computer temperatures are crazy. Doing very little the temps are between 70-89 degrees celsius on a regular basis.

    I don't know if this is apples attempt at ruining older hardware to get users to upgrade, but if not this is terrible engineering. I just reinstalled Snow Leopard and temperatures are maxing out performing the same tasks as mountain lion at 60 degrees.

    Is anyone else with MBPs having these kind of extreme heat issues? I have at mid 2010 macbook pro.
  2. GGJstudios macrumors Westmere


    May 16, 2008
    The Intel processors used in Macs are designed to automatically shut down to prevent damage if they truly overheat. CPU Tjmax = 105C (221F), GPU Tjmax = 100C (212F) on i3, i5, i7 processors. (Source: Intel)

    If you're not already using it, iStat Pro (free) or iStat Menus ($16) will give you accurate readings of your temps and fan speeds, among other things.

    Unless there is a rare defect in a Mac, most temps are well within the normal operating range, considering the workload being put on it. Websites with Flash content, games and other multimedia apps will put higher demand on the CPU/GPU, generating more heat. This is normal. If you're constantly putting high demands on your system, such as gaming or other multimedia tasks, expect temps to rise and fans to spin up accordingly. It's just your Mac doing its job to maintain temps within the normal range.

    It is also quite normal for your Mac to become extremely hot to the touch during intensive operations. The aluminum body transfers heat more effectively than other materials used in computer casings, so you will feel the heat more. This doesn't indicate that it's overheating and will not harm the computer to be hot to the touch.

    Your fans are always on when your Mac is on, spinning at a minimum of 2000 rpm (for MBPs) or 1800 rpm (for MBAs, MBs and minis). iMacs have 3 fans with minimum speeds in the 800-1200 range. They will spin faster as needed to keep temps at a safe level.

    If your fans are spinning up without increased heat, try resetting the SMC.
    (PRAM/NVRAM has nothing to do with these issues, so resetting it will not help.)

    The intake and exhaust vents are in the back of the computer near the hinge on all Mac notebooks (except the new MBP with retina display, which has intake vents along the sides at the bottom). The iMac vent is a slot on the back near the top of the computer. Make sure the vents remain unblocked to allow your computer to perform at its best.

    Learn about the fans in your Mac
    Apple Portables: Operating temperature

    For Flash-related issues:
  3. chrisby thread starter macrumors newbie

    Jul 26, 2011
    Thank you. I've done most of this before with Lion. There is a big difference between shutting down to prevent damage and making my lap so hot I can't use the laptop. I am back on snow leopard and truth be told, I like it much better.

  4. iLog.Genius macrumors 601


    Feb 24, 2009
    Toronto, Ontario
    Everyone I know that have upgraded to Mountain Lion, including myself, have experienced it and is especially the worst when the computer is being charged. It doesn't seem to matter what you're doing, the computer will just get warm until you restart the computer and only then the temperatures become much more acceptable and tolerable.

    There seems to be no change in temperature when you're running off battery.
  5. Rossagues macrumors regular


    Aug 12, 2012
    Late 2009 model.. mines 60-90.. all the time. Got chrome and iTunes running at the moment. 5 Hours battery at most.. Gets me so angry!
  6. Krazy Bill macrumors 68030

    Krazy Bill

    Dec 21, 2011
    That makes about a dozen of us here on Snow Leopard now. (I think). We should all form a secret society with special handshakes and stuff. :D
  7. scottsjack macrumors 68000

    Aug 25, 2010
    My late 2008 MBP also runs hotter on ML. You can almost watch that battery level go down on the discrete Nvidia card. Unless I really need it I have to run on wimpy 3400 video.

    Every so often I pop a Snow Leopard disk into a Mac. The colorful Finder and aqua drag bars sure look great. Unfortunately (as I recall) OS X has gotten to the point where Aperture and maybe iPhoto files don't interchange between ML and SL versions.

    Also, as much as I would rather look at Snow Leopard it turns out that Lion benchmarks faster and Mountain Lion even faster using Geekbench and Cinebench on my three Macs.
  8. Krazy Bill macrumors 68030

    Krazy Bill

    Dec 21, 2011
    It's a mixed bag. The reviews I've seen gives SL a "slight" edge. Of course this depends on the task/app and overall it's negligible. File I/O seems faster in SL for me. Certainly no reason to cling to Snow Leopard though.

    Other than Spaces/Expose', I stay with it because of the simple no-frills UI (by comparison to the Lions). It just makes sense to me and I'm not much for "fluff" or eye-candy.

    Also, the battery life. :)

    As far as SL running cooler, I can't tell any difference.
  9. chrisby thread starter macrumors newbie

    Jul 26, 2011
    I can't help but play around with these a little bit. Snow leopard was working great, but I had to see if this was 10.8 specific. I reinstalled 10.7.4. While indexing installing apps and copying about 100GB of data back onto the hard drive, the CPU never got above 74 degrees. I think mountain lion has some problems that Apple knows about. These problems are causing the CPU to be used inefficiently resulting in battery drain and hot laptops. What other reason would they have to remove the time remaining from the battery monitor?

  10. Krazy Bill macrumors 68030

    Krazy Bill

    Dec 21, 2011
    Because people were calling in thinking the "calculation" was the word of god. It's just a guess.

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