MacBook Air (2009) stuttering with Windows7 64bit

Discussion in 'Mac Basics and Help' started by Erehael, Feb 5, 2010.

  1. Erehael macrumors newbie

    Joined:
    Feb 5, 2010
    #1
    Hi,

    I've installed Win7 64bit using Bootcamp on my MacBook Air (2009 model).
    The installation went through without any problems. I then installed Bootcamp 3.0 from the Snow Leopard CD and then Bootcamp 3.1 using Apple Software Update.
    Everything seems to be working fine (sound, wifi etc).
    However, whenever I start to work with the computer (open some application, compile some code etc) I get some random stuttering where the whole computer seems to stall for half a second or so. It's especially noticable when I'm listening to music.
    After some googling, everything points to a bad driver. Running the DPC Latency Checker program supports this theory (see attached screenshot). Whenever the computer stutters it records a big red spike.
    I tried to disable any device in the device manager I could think off (audio, wifi, bluetooth etc). Nothing helped.
    I think it's got something to do with the SSD since the spikes are the worst whenever it loads something from the harddrive.

    This is starting to drive my crazy, maybe someone here has any idea. Any help is greatly appreciated.

    Here are the specs of the MacBook Air:
    128 gb SSD
    2gb RAM
    Core2Duo 2.13ghz
     

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  2. dandaman2 macrumors regular

    Joined:
    Aug 18, 2008
    #2
    HD troubles of some sort fit best with your description. Since you only have 2 gigs in there, I HIGHLY recommend a downgrade to 32bit windows. 64bit simply is not worth the price if you have less than four gigs of RAM, and downgrading to 32bit will also help dramatically with compatibility. Even if someone more familiar Boot Camp can identify the true source of the problem, it's probably a good idea to do the downgrade anyways.
     
  3. Erehael thread starter macrumors newbie

    Joined:
    Feb 5, 2010
    #3
    Alright I just installed Win7 Pro 32bit and I have the exact same stuttering problems.
    I wonder if it's not a general issue with my Air. I'll try to push it in Mac OS X and see if I get stuttering there.
     
  4. godudi macrumors newbie

    Joined:
    Feb 6, 2010
    #4
    I have the same MBA model and the same audio stuttering problem

    You are not alone, and as far as I know there are many others who suffer from the same annoying problem.

    I tried everything, reinstalling the OS from scratch, different drivers from realtek, disabling other HW such as WLAN etc., but no success.
    I am running windows 7 32 bit.
    Bootcamp updated to v3.1
    Realtek driver updated to v2.41

    I also thought it might be a HW related issue, however the problem doesn't exist on MAC OS.

    HELPPPPPPPP :(
     
  5. Erehael thread starter macrumors newbie

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    Feb 5, 2010
    #5
  6. AllanMAX macrumors newbie

    Joined:
    Feb 9, 2010
    #6
    Help!!

    I have exactly the same problem on my MBA with 128GB SSD.
    Has anyone found a solution?:mad:
     
  7. ayeying macrumors 601

    ayeying

    Joined:
    Dec 5, 2007
    Location:
    Yay Area, CA
    #7
    Boot Camp 3.1 fixes this problem.

    Also, if you're experienced, you can remove the logic board and see if the grounding pin that touches the base of the keyboard is actually touching. Last time I removed and installed my logic board, that ground wasn't touching and caused a whole lotta latency problems.
     
  8. dandaman2 macrumors regular

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    Aug 18, 2008
    #8
    is there a windows equivalent to disk utility? I don't use windows so I wouldn't know...
     
  9. kaa4ever macrumors newbie

    Joined:
    Feb 23, 2010
    #9
    Im having the same problem on my MBA.
    Boot Camp 3.1 didnt fix anything.
    Anyone else got a suggestion to fix the problem?
     
  10. newdeal macrumors 68020

    Joined:
    Oct 21, 2009
    #10
    ...

    its related to the crappy SSD apple uses in the air most likely, its possible that in boot camp windows can't detect you have an SSD so you may want to search the web for windows 7 ssd tweaks and do those such as disabling auto-defrag etc etc etc especially since the apple ssd doesn't support trim. If you notice windows boxes have times when you aren't using them and yet the hard drive light blinks every once in awhile that coupled with an SSD that has poor performance can cause the stuttering
     
  11. ayeying macrumors 601

    ayeying

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    Dec 5, 2007
    Location:
    Yay Area, CA
    #11
    Not true. The stuttering is caused by latency in the motherboard, not the SSD. The stuttering you're talking about is the lag between the SSD completing one task before moving on to the second one.

    Furthermore, you really don't need to do any of those SSD tweaks. I never found a reason to do them on my former MacBook Air with an SSD. The stuttering did fix itself after a logic board replacement, so it's actually a hardware issue on the logic board, not the SSD.
     
  12. Dan73 macrumors 6502a

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    Jul 30, 2009
    #12
    What? I'd never recommend 32 bit to anyone anymore.
     
  13. newdeal macrumors 68020

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    Oct 21, 2009
    #13
    since the apple ssd doesn't supoprt trim and is very low performance over time it will begin to lag every time it tries to write to disk. Since windows does a ton of writing due to the internal defrag often doing those tweaks will decrease the number of write requests the OS sends and hence reduce the burden on the ssd and increase performance. its worth a try anyway
     
  14. ayeying macrumors 601

    ayeying

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    Dec 5, 2007
    Location:
    Yay Area, CA
    #14
    Windows don't have an internal defrag that goes on the fly, instead it defrags on a schedule which is set for a Weekly defrag on default. OSX has automatic defrag.

    Those tweaks, I've done before, not much difference in terms of performance. Most of the time it'll decrease performance because Windows aren't able to adapt to how the user uses the system. Believe it or not, Windows and OSX have some minor adaptive performance improvements built in. OSX has scripts to clean the system along with cache for applications, Windows has cache and prefetching.
     
  15. kaa4ever macrumors newbie

    Joined:
    Feb 23, 2010
    #15
    So you say its a hardware fault and i need to get a new motherboard?

    Well if thats true, then should't the warranty pay for it then?
    They do sell it on the promise that i works with windows..
     
  16. ayeying macrumors 601

    ayeying

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    Dec 5, 2007
    Location:
    Yay Area, CA
    #16
    It's not 100% hardware fault but I do believe hardware plays a role in it. Remember, even though on papers all boards have the same parts and configuration, they're not created equal.

    I highly doubt Apple will replace your system just to fix a problem in Windows. They'll just blame it on Windows.
     
  17. kaa4ever macrumors newbie

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    Feb 23, 2010
    #17
    Think your right, guess theres nothing to do, but sit and wait for Apple to release some new drivers that will fix the issue. If that ever happens :(
     
  18. ayeying macrumors 601

    ayeying

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    Dec 5, 2007
    Location:
    Yay Area, CA
    #18
    Boot Camp 3.1... i think its 3.1 or is it 3.0.1? have the best drivers so far. It'll limit the latency lag as much as possible. You can try those, if those don't work then you're really out of luck here.
     
  19. ExcelonGT macrumors regular

    Joined:
    Feb 9, 2008
    #19
    I don't think this is a hardware issue and here is why:

    I have a Rev A MBA (1.8ghz, 64gbSSD) purchased in Feb 2008. Ive run OSX 10.5 Leopard for a year, and Win7 x64 Beta since Feb 09, Win 7 x64 RTM since August 09.

    Just this week, I reinstalled Windows 7 x64 fully legit version. I installed the OS as my only OS, and installed Bootcamp 3.0 and then 3.1.

    Ive NEVER had this stuttering problem until now. I was running Bootcamp 2 under Windows 7 before and didnt have any problems with stuttering audio.

    My current version of Realtek drivers is 6.0.1.5936
    I really think this issue is caused by the Realtek Driver and/or Bootcamp 3.0/3.1

    Im not going to even bother taking this issue to the Apple "genius" because I dont think they will do jack. Lets figure this issue out here..
     
  20. ayeying macrumors 601

    ayeying

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    Dec 5, 2007
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    #20
    Um... I remember the latency issue was related to the graphics card downclocking to save power, not an issue with the sound card?
     
  21. ExcelonGT macrumors regular

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    Feb 9, 2008
    #21
    Please explain.

    I've been using Win7 on my macbook air since last year have have not experienced this latency issue until just recently, when reinstaling OS and going with Bootcamp 3.1
     
  22. ayeying macrumors 601

    ayeying

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    #22
    Read on:

    http://forums.guru3d.com/showthread.php?t=291542
     
  23. Gta007 macrumors newbie

    Joined:
    May 22, 2010
    #23
    I got the same problem...

    the only solution is CPUGenie and set 800Mhz max.

    Macbook air 128GO SSD, win7 x64, Bootcamp 3.0 & 3.1 update:

    [​IMG]

    Any ideas?
     
  24. Runwin macrumors newbie

    Joined:
    Oct 13, 2010
    #25
    Win7 64 Fix for Stuttering Audio and high DPC's!

    I had the same issue, and I ran the DPC latency checker and found extremely high DPC counts, which will always cause stuttering/dropouts.

    Turns out another gentleman has already figured out the issue (Thanks T1mur!!!), which has mainly to do with the bootcamp.exe process being poorly written for symmetric multiprocessing.

    Read this thread for the fix and discussion: http://discussions.apple.com/thread.jspa?threadID=1876027&tstart=0

    To cut to the chase, just download the "bootcamped" scripts that he's posted, available here: http://www.screencast.com/t/7HhqtFZLpf

    If you're running Snow Leopard and have the latest 64 bit bootcamp installed, you'll have to make a few changes to the scripts. The scripts all point to the process named "KbdMgr.exe" but in the latest Bootcamp it's called "Bootcamp.exe". You'll need to change every instance of the former and replace it with the latter (an easy way to do that is to open them all in Notepad++ and use the "replace in all open documents" function) and run the script "Start Boot Camp.CMD" This script just tweaks the bootcamp.exe process priority and affinity for one CPU, causing it to behave. If you run DPC latency checker and keep it running while you start the script, you will see an *instant* improvement!

    This is the best option for anyone having this problem with Bootcamp, at least until Apple decides to fix their drivers.

    Good Luck!
     

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