1. Welcome to the new MacRumors forums. See our announcement and read our FAQ

Air EXTREMELLY slow with Cinema Display

Discussion in 'MacBook Air' started by candeo, Sep 10, 2009.

  1. macrumors newbie

    Everytime I connect my Macbook Air rev B with 128 SSD to my 24 cinema display, the Air gets REALLY slow, to the point that I can't anything on it anymore.
    Does it happen to anyone else? It seems to be a recent issue, as I did not notice it before, or maybe it was just less obvious.
  2. macrumors 6502a


    I use my Rev B MBA on my LED Cinema Display all the time. It works great except for the occasional "flicker". I think its because the MBA can't keep up with the high refresh rate at the highest resolution.

    Are you up-to-date on your Software Updates?
  3. macrumors newbie

    Yes, I have installed all software updates.
  4. macrumors 6502a


    As an experiment, have you tried dropping the resolution to see if that has an effect?

    Also, check your "energy saver" preferences to make sure you're using the full potential of the CPU (i.e., "higher performance" over "better battery life").

    And you didn't install CoolBook or any other utility to slow down your clock speed did you?
  5. macrumors newbie

    Looking at the activity monitor, it seems like after a while the kernel-task is using more than 50% of the CPU, and that is what causes the issue. If I disconnect the cinema display and then reconnects, it is better. Anyone else with this issue?
  6. macrumors 601


    Never had a problem on mine. It works wonderfully. Sure, an occasional flicker, but never affects the MBA's operations. Maybe you have something set wrong??? I don't know. I have even played HD video on a 30" display.
  7. macrumors 6502


    I'm with Scottsdale on this one: I've used my Rev B with my 24" ACD without any problems at all. I'd be interested to know what happens if you connect your MBA to another ACD - whether the same behaviour manifests itself with a different display. Do you have an Apple Store nearby?
  8. macrumors 601


    That's probably the best test first. I would have to assume though that the problem is in the logic board for the Nvidia output via Mini Display Port.

    I would hope for your sake that the problem is with the ACD (meaning not your MBA), but I just don't see how a problematic display or even cable would cause computing slowdowns.
  9. macrumors newbie

    I'll go to an Apple store and try to check with another display. But the issue is that it takes a while before it happens. The Air gradually becomes hotter and hotter, until I have this issue with kernel_task.
  10. macrumors regular


    mine does this but i never tried dc'ing the cd. just assumed the kernel was an issue with the mba design, chugging along on more than it could chew.
  11. macrumors 6502

    I had the same issue but with network access as soon as I closed my Airport connection it went from back to normal
  12. macrumors 6502a

    Sounds like the classic signs of an overheating air and a processor trying to manage that heat by down clocking it self. I bet if you watch the CPU activity monitor it looks like a series of peaks too right?

    Bring it in to Apple and see if you can get them to replace it. Dont bother with the new ACD, the issue seems obvious now that you gave more detail.
  13. macrumors newbie

    Well, I am "somewhat" glad that it is happening to other people as well. But if it is an issue of the Air overheating, why is it only happening when I am connected to the CD? Also, I thought that the overheating issues were only with Rev A, no?
  14. macrumors newbie

    What is considered "Overheating"? It looks like my CPU is pretty much always around 70 degrees, and the fan is turning at 6200 rpm, even when not connected to the CD. But I don't really hear the fan, and I don't feel the heat. Also, the computer has been working fine, and fast, except when I get this issue.
    Most of the time, I am running a couple Java applications (for real time trading quotes), while doing some browsing and emailing.
  15. macrumors 6502

    Are you running the machine in clamshell mode when connected to the monitor? A fair amount of the cooling happens through the keyboard and the DVD pulls a good amount of power, so it could be enough to tip it over the edge, depending on ambient temps, etc.

    You could look into coolbook and/or redoing the thermal paste (or asking them to do so at an apple store .. iirc, I remember threads where people had this done at their request).

    The Rev As seemed to have a higher probability of over heating vs the Rev B, but a Rev B is no means a guarantee (esp. if you have a terrible thermal paste job or are running in a warmish room to begin with, etc).

    Good luck.
  16. macrumors 6502a

    Rev A?

    Any experiences with the REV A 1.8 GHZs (64GB SSD) with the 24" ACD?

    I am wondering if it is a good experience or not
  17. macrumors newbie

    No, I am not running "clamshell", the laptop is open. 10 minutes after I connect the display, kernel_task goes over 100. A couple minutes after I disconnect it, it goes back to 3.
  18. macrumors newbie

    Hum...It looks like the issue is mostly when I listen to streaming radio through the CD's speakers (connected with USB). When I use the screen only for "display" it does not seem to happen.
    When I listen to the radio directly on Macbook Air I don't have this issue. It is a flash-based live broadcast from KCRW.com...
  19. macrumors 6502

    Flash is "the evil" on OS X .. that makes sense.

    PS. Sorry, I misread CD as the DVD and not "Cinema Display".
  20. macrumors newbie

    Yes, looks like it is flash indeed. When I play music through Itunes, it works fine, so it is not from the speakers or the USB port.
    It's crazy because when I listen to the same streaming radio directly on the computer, it's fine.
    Sorry for all the posts about this, but hopefully that will help someone else if the same happens to them. I will be installing SL this weekend, hopefully it will not make it worse.
  21. macrumors 68040


    Boy I hope I don't experience this. I just ordered up a 24" ACD, and am planning on putting my MBA to the task. I hired some new employees, and one of them gets my 20" iMac.

    Figured I would save some coin, and utilize my Rev B SSD at home/Road/ and work. I am preying it holds up to my tasks; I will be pounding some pretty heavy tasks. VMware/Mail/Entourage/Office Networking etc...

    I am preying it hold up with this new ACD.
  22. macrumors 601


    WILL NOT WORK. You need a rev B/C MBA to drive the 24" LED ACD.
  23. macrumors 601


    I don't think what the OP has experienced is or should be expected as normal in any way. For all you listed, it will be more than enough. I don't even see how this applies if it now is supposedly the Flash plug in but before only happened when plugged into a 24" LED ACD.

    I must say that my rev B 1.86/128 GB SSD MBA was BY FAR my greatest Mac experience EVER. And the 24" LED ACD makes the experience with my MBA great too.
  24. macrumors newbie

    Scottsdale, did you try listening to streaming audio (flash one), via your display's speakers? I would be interested in knowing if the issue only happens to me.
    I agree with you though, I love my Macbook Air and would not change it for anything. No issues at all running VMware FUsion, entourage etc...(even if it is slower of course than working with OS X). I also do some heavy Java stuff and it is fine.
  25. macrumors 601


    Maybe you're trying to do too much with it. I don't recommend anyone use it with Parallels or Fusion because there isn't enough RAM.

    Here is the thing with the Air; it has only 2 GB RAM, so you're limiting OS X and Windows to only 1 GB RAM (or some variation adding up to 2 GB). If someone wants to run Windows on the Air, they really should do it in Boot Camp.

    It seems to me like you may be using the MBA like NOT intended. Next, no Mac is great with Flash. You're working around the acceptable CPU clock speed to deal with Flash, but you also have your resources tied up into Fusion and Windows.

    Then you also mentioned "heavy stuff."

    The MBA is right for people who use OS X. It is right for people who use most apps but not all. It is right for doing one intensive task at a time.

    It is not right, in my opinion, for Windows virtually at the same time as OS X. It has 2 GB RAM which is fine in OS X but deadly to share. Also remember the 9400m is sharing the same memory too!

    The MBA is also not right for people who run many intensive tasks at the same time. Sure you can have mail open, a few Pages documents, an Excel spreadsheet, and a video. But you cannot have Windows sharing half the RAM and all those same apps running in BOTH Windows and OS X.

    You also cannot expect multiple videos with a few Flash pages in FireFox and several plug-ins going while limiting the RAM.

    This is a problem of what people consider "normal" and what I consider normal. I am always reading someone say I have 14 FireFox pages going (a few plug-ins and Flash probably included), I have five other apps open, and I am trying to run a YouTube video in SD and the fans are blowing at 6200 rpms! Well, this is the problem.

    To me it's NOT normal to want to run Windows at the same time as OS X, but if you do want that, you should honestly select a different Mac. Unless you're aware that you're sharing the resources and GPU RAM on both sides and running non-intensive and limited number of apps on both OSes.

    If you want to run Windows on an MBA, it's great in Boot Camp! This is a limitation of the MBA. Another limitation is operating many apps and many Safari or FireFox tabs at the same time. I like to think that I cannot do 17 things at a time so why would I leave all those apps open. Here lies the differences with all the heat/fan complainers - they're doing too much.

    The limitations of the MBA are that if you want it to do everything you want at fast speed, fairly cool, and Mac-like, you have to realize what's normal for an MBA. If I have Safari running and Flash pages are hitting the CPU you can be certain I don't have a bunch of other apps going. I leave Email and Pages open while working on Safari, but I don't have PS running with other apps at the same time I am actually surfing FireFox Flash pages.

    I guess to some people it's normal to be sharing out system resources between two OSes and still expect amazing performance from the MBA but I
    know its limitations.

    I wouldn't expect there is anything wrong with the OP's MBA or ACD, I think a Mac Pro might work better for all that than the MBA. I seriously think the OP has demanded too much from the MBA and that's just a difference in opinion on what's normal.

Share This Page