MBA Base is Hot...

Discussion in 'MacBook Air' started by JoelBC, Nov 9, 2014.

  1. JoelBC macrumors 6502a

    Jun 16, 2012
    I have a mid-2012 MBA that is almost two years old.

    I remember that when I first got my MBA I could sit on my couch for hours and the laptop never got hot.

    When I now use the MBA while sitting on my couch the base / bottom gets hot to very hot quickly...the battery health is 83% with 92 cycles.

    Would appreciate feedback as to what this my battery dying to the point where the MBA will only work when plugged in (as has happened to my friends' older MBP), etc.

  2. SusanK macrumors 68000

    Oct 9, 2012
    My mid 2012 MBA stays comfortable on the couch, recliner etc. It only got hot once when it was almost new. I was playing Chess. Stopped playing chess. It's still good.

    I know that's not much help other than we have MBA's about the same age. I bought mine on Black Friday 2012.
  3. GGJstudios macrumors Westmere


    May 16, 2008
    The heat has nothing to do with your battery. It's normal that your Mac gets warmer to the touch under heavy workloads. The primary sources of heat are your CPU and GPU, not your battery.

    If you're not already doing so, use iStat Pro (free) or iStat Menus ($16) to get accurate readings of your temps, fan speeds, etc., rather than relying on your sense of touch or sound. A forum member has posted a copy of iStat Pro that has been "tweaked" to enhance compatibility with recent OS X versions. You can download it here.
    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)
    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. For Flash-related issues:
  4. JoelBC thread starter macrumors 6502a

    Jun 16, 2012
    Appreciate the detailed response and note:

    1. I am neither gaming nor using flash so this is not an issue but I am using a VM so perhaps this is stressful.

    2. I am running iStat Pro so will monitor my temperatures and report bck.

    Again, much thanks.
  5. motrek macrumors 68020

    Sep 14, 2012
    Please go to the Activity Monitor and click on either the CPU or Energy tabs to see what is using your CPU power. This is almost certainly causing your computer to heat up.

    Another potential but less likely cause is if you're powering/charging external USB devices.


    Good post.

    FYI, recent MBAs (or at least the 2014 11" MBA) have fans that spin at a minimum of 1200 RPM.

    This unfortunately caused a problem for me more than a year ago. I bought a 2013 MBA and imported my data and settings from my old MBA. This included smcFanControl, which set the minimum fan speed to 2000 RPM (as it was with the older laptop) instead of 1200 RPM. That caused an audible whine which annoyed me and I ended up returning the laptop. I only recently figured out what went wrong. :(
  6. GGJstudios macrumors Westmere


    May 16, 2008
    Yes, I've noticed that several newer model Macs have slightly different specs, so I've edited my standard post for future use.
  7. Meister Suspended


    Oct 10, 2013
    A while ago I recorded uncompressed video through a 13" mba and it got boiling hot. I mean you could literally burn your fingers in the area below the screen.
  8. JoelBC thread starter macrumors 6502a

    Jun 16, 2012
    Although it fluctuates quite bit I have included a screen shot from Activity Monitor, any seems that Parallels is using a lot of CPU processing...worth perhaps doing is trying o use my MBA *without* Parallels a seeing how hot it gets.

    Not charging / powering any USB devices.

    I have also posted a screen shot from iStat Pro, any insights...granted that when the screenshot was taken the MBA does not seem warm / hot.


    Attached Files:

  9. Gav2k macrumors G3


    Jul 24, 2009
    Are you running windows when it's 'hot'

    Also when was the last time you cleaned your fan and heatsink??
  10. JoelBC thread starter macrumors 6502a

    Jun 16, 2012
    I confirm that running Parallels/Windows really heats things up...10 to 15 minutes of use increased the CPU temperature to 65 degrees while not more than two to three minutes after shutdown reduced the CPU temperature to 51 degrees and it is still this normal?

    I have never done this...instructions would be greatly appreciated.
  11. Gav2k macrumors G3


    Jul 24, 2009
    Yes running windows will heat any MacBook up unless it's done via boot camp as your running an os over an os.

    You just need the correct driver to remove the screws from the bottom. The panel comes off then you blow the fan through with compressed air. It takes 5 minutes and guides are availible on ifixits website.
  12. motrek macrumors 68020

    Sep 14, 2012
    No, it isn't. If your Windows VM is using a lot of CPU power then you will have to go run Task Manager in Windows to figure out why.
  13. MacLC macrumors 6502

    Oct 18, 2013
    There are a few sites with great instructions for ripping apart mac laptops. ifixit or macfixit is one of them. If you go that route, what I found helpful with my old Powerbook is putting screws in bags for every step I did. Otherwise it's hard to tell the difference between 4mm and 4.5mm or 6mm and 6.5mm screws from separate steps.

    Also, for my work Dell laptop I got a "laptop cooler". They run $10-$60. Mine was probably $20. It is basically a plastic frame with a USB-powered fan. Simple as it is, before getting one my laptop fan would go full-throttle after 5 minutes of sitting idle, the surface it sat on got hot, and the keys were sometimes too hot to type on.

    With a laptop cooler in operation, the fan stays in low power and all surfaces stay comfortable to the touch. I don't even know what brand mine is, but for $20 or so you can't go wrong whatever brand you get.
  14. motrek macrumors 68020

    Sep 14, 2012
    This is good advice if you are constantly running things that take a lot of CPU power.

    So far we have no indication that the OP is intentionally doing anything that requires enough CPU power to heat up his entire laptop, dirty fan or not.

    So, OP, before taking anything apart, definitely check Task Manager in your Windows VM to see whether or not there's something unexpected that's taking up all your CPU power and heating up your laptop.
  15. keysofanxiety macrumors G3


    Nov 23, 2011
    Yes, completely normal. The CPU/GPU power required to run a virtual machine is a lot. It's important to consider that the MacBooks are made out of aluminium. They're designed in such a way that the case is used to discharge heat, so even when they feel hot they're often running a lot cooler than equivalent Windows laptops under stress.

    The TJ Max for your CPU/GPU is between 95-100C, so unless it's getting above 90C with sparse use then you needn't worry. If it gets to those sort of degrees with prolonged use (2+ hours), that's an unfortunate limitation of the MacBook Airs, but a well documented one. Basically from what you've described, you don't need to be concerned. :)
  16. JoelBC thread starter macrumors 6502a

    Jun 16, 2012
    Attached is a screenshot of Windows' VM's Task manager...I don't see anything abnormal, do you or anyone else?

    Appreciate knowing that things are in a normal -- albeit warm / hot -- range

    Attached Files:

  17. motrek macrumors 68020

    Sep 14, 2012
    No, it isn't.


    Nope, looks fine. Odd. I went back and looked at your screen shot of iStatPro or whatever it's called, and it's showing that your fan is running at 2000 RPM and the CPU temperature is 48 degrees, which is consistent with an idle system. And all the other temperatures are lower.

    Are you sure the computer was hot when you took the screen shot? Because I'm kinda guessing that it wasn't.

    Please realize that the amount of heat your computer puts out is dependent on what you're doing with it at the moment, it's not a constant. If you start running something intensive (in a VM or not) then it will heat up in less than a minute and as soon as you stop it will cool off in less than a minute. So just because it gets hot sometimes doesn't mean there's something inherently wrong with it.
  18. keysofanxiety macrumors G3


    Nov 23, 2011
    It is on a MacBook Air.
  19. motrek macrumors 68020

    Sep 14, 2012
    No, it still isn't.

    If the guest operating system is idle then there's no reason why the host operating system wouldn't also be essentially idle. Maybe it takes a few extra percent CPU power to keep the guest OS ticking over but that's it.
  20. keysofanxiety macrumors G3


    Nov 23, 2011
    A standard MBA with a 1.4 i5 and only 4GB RAM? Or an even older CPU? Open up a VM and it's gonna hammer it. I've seen this happen, with my own eyes -- many of my friends have MBAs. You can literally see the CPU usage and RAM shoot right up when you're running a virtual machine. You can hear the fans revving up. You can feel the system getting warmer.

    Why are you being so obtuse? Seriously.

    OP's question was: is it a problem. It isn't because it's normal for the CPU/GPU usage to go up when running a VM, and as long as the temps don't exceed 90C or so then it's really not an issue.
  21. motrek macrumors 68020

    Sep 14, 2012
    I'm seriously being so obtuse because you're taking a complicated issue and simplifying it to the point where what you're saying makes no sense.

    It's like if you claimed that car engines run at 7000 RPM all the time. No. It depends on what gear you're in and how fast you're going. Just because you drove a car once and you checked the tachometer and it said 7000 RPM doesn't mean that everybody's car runs at that speed all the time.

    If your guest OS is busy then it will use a lot of CPU power. If your guest OS is idle, then it won't use a lot of CPU power. They don't necessarily use a lot of CPU power all the time. It's as simple as that.

    No, again, it's not normal at all.

    And it is a problem. Maybe the OP's computer won't actually break from overheating but it's a problem. A hot computer makes it uncomfortable to use on a lap and it also means the computer is using a lot of power, which will decrease battery life. So it's worthwhile to try to diagnose what's going wrong and not just make blanket nonsensical statements like "VMs use a lot of CPU power."
  22. JoelBC thread starter macrumors 6502a

    Jun 16, 2012
    Appreciate all the feedback and hope we can get this sorted...a little more information:

    1. MBA is a mid-2012 fully loaded meaning I7, 8GB of RAM and 256GB SSD drive. No more debate about the unit.

    2. The iStat Pro image that was posted was *before* starting the VM to show the fan speed in response to the previous comment / poster.

    3. The Task Manager image is when the VM has the normally loaded apps running.

    So with that said I believe the landing points are:

    1. It is a problem because the MBA is damn hot on my lap when running the VM.

    2. It is not a problem because this is normal behavior be design.

    If I do not have the correct then please correct it as I want to make sure my understanding is correct.

    Thanks to all.
  23. motrek macrumors 68020

    Sep 14, 2012
    Problem? Yes and no. Your computer will not self-destruct, so don't worry about that. I haven't worked at Apple but I've worked at other companies that design electronics and of course they design and stress-test them such that they won't break under normal operation. Imagine a bunch of MacBooks running flat-out for days on end in a special chamber that simulates high temperatures and high humidity. This is what they're designed for. Because it won't do if a bunch of people in hot/humid South American countries start returning all their Apple laptops because they break as soon as they play a video game or whatever.

    That being said, if your laptop is running damn hot, there should be a reason for that. It might not be a reason that's immediately obvious. Maybe your copy of OS X is indexing all your files, which it does automatically in the background sometimes. Or maybe your copy of Windows is running a virus scanner in the background and you didn't notice. Or maybe you're looking at a web page in either operating system that has some poorly-written Flash advertisements that are taking up all your CPU time and burning your lap.

    So, it sucks if your lap is hot and your battery life is terrible for a reason you don't understand. So next time it gets hot, check out Activity Monitor in OS X and Task Manager in Windows and see what's taking up all your CPU power. Maybe it's something you don't want or need and you can force it to quit or uninstall it or whatever. Or maybe it's something you DO want it to be doing, and at least you will know what's going on.
  24. JoelBC thread starter macrumors 6502a

    Jun 16, 2012
    I will also add that from my experience -- as a sample of one -- the following with respect to the use of VMs:

    1. If one starts up a VM but does not use any of its apps [i.e. boots / starts up in Win7] then the increase in the CPU temperature is nominal [i.e. 48 degrees moves to 50 degrees].

    2. If, on the other hand, one uses [even light use] the VMs application then the temperature increase is temperature is large....for example, light use of Excel [small spreadsheet, not calculation intensive] and IE raised the temperature from 50 degrees to 73 degrees].

    Hope that adds to the discussion.
  25. keysofanxiety macrumors G3


    Nov 23, 2011
    Hi Joel,

    I mentioned it earlier in the thread that despite motrek's claims to the contrary, even light tasks on a virtual machine on a MacBook Air will have a significant impact on the temperatures of your CPU. It happens with my MacBook Pro. It happens with my friends' MacBook Pro. It happens with work colleagues. It happens with other people who have MacBook Airs.

    Running a virtual machine does take a lot of resources - you're running two operating systems simultaneously. You've got a dual-core i7 with 8GB RAM. It will run a virtual machine perfectly. However it's perfectly normal for the temperatures to ramp up, and for the fans to start ramping up too. As mentioned, as long as the CPU doesn't exceed 90C then there's no need for concern.

    This whole rhetoric about 'we need to diagnose the heat problem' is absolute hogwash. There isn't a temperature issue because your CPU isn't getting anywhere near the TJ max. Computers, especially ultra-portables, will have a noticeable impact with CPU/RAM usage when running a virtual machine. It's perfectly normal. There isn't a problem, and there's no need for concern - unless the temperatures are getting beyond 90C - which it looks like they aren't.

    So we've identified that:

    1) Your CPU/GPU ramps up when running a virtual machine (despite motrek's insistence, this is perfectly normal)
    2) Although the MacBook feels hot to the touch, it's not getting anywhere near its thermal limit so it's not a problem that needs to be identified or addressed.

    Hope this helps.

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