iMac freeze until mouse goes on dock

Discussion in 'Mac Basics and Help' started by ajalro, Apr 4, 2011.

  1. ajalro macrumors newbie

    Apr 4, 2011

    I noticed this problem a few time since I bought my iMac 21,5" 3.06ghz 4gb ram (late 2009) on october 2009
    Sometimes it happens that iMac freeze also for very simple task (ie selecting some files inside finder), I see the small wheel multicolor and it stalls so until I move the mouse (wheel multicolor) on the dock of the app at the bottom of the screen, when I do that the iMac come back normally.
    I don't use heavy application of editing video/audio, I configured my iMac for 2 account (me and my girlfriend), she use only browser with a dozen of open tab (tab, not windows) sometimes 1 word doc (office for mac), that's all for her.
    I use some server app for iphone (airvideo, wine server,xmarks) or backgrounding app (little snitch, eyetv) and I use moreover browser, itunes + tune up, iphoto, imovie, transmission, quicktime.
    I noticed that very often my problem occurs when I
    select files in a finder window or itunes window
    open eyetv screen window
    open video in quicktime
    there is not a rule, but it seems to be related to video activity
    Because of I was thinking that the reason was the ram, I bought 2x4gb of new ram, so now I have 2x2gb of ram installed by the manufacturer plus 2x4gb of new ram, for a total amount of 12gb, but the problem is still here

    I tried to reinitialize macosx, to repair permission, to verify hard disk, to perform apple hardware test, to perform memtest/rember, all test were passed with OK
    I tried also to reset PRAM/VRAM and to reset SMC....

    I dont'k know whatelse try... all seems to be ok, but I experience the problem yet.
    Someone could please help me and suggest something???
  2. JJP9398 macrumors member

    Jan 31, 2009
    I also have a similar problem but mine is usually when I'm surfing in Safari. I've even went as far as reinstalling Snow Leopard but the problem just came back. I think that it might have something to do with flash player. I haven't figured a way to fix it yet.
  3. ajalro thread starter macrumors newbie

    Apr 4, 2011
    Hi JJP9398,

    you're the only one I found that he has the same situation! freezing until moving mouse on dock!

    If the problem is the flash, is it possible to disable flash completely from mac anche install some tricks that inform us when in a web page there is a flash content and to load it only after our ok???
  4. mawan macrumors newbie

    Jul 26, 2009
    I am too having the same problem.
    Are we the only people having this issue ?
    I've been searching the internet but can not find the solution.

    I hope someone can give us the solution...
  5. JJP9398 macrumors member

    Jan 31, 2009
    There is a app called click2flash that disables all flash on a page until you click on it. I tried it out for a little bit but didn't really like it. The funny thing is, my Macbook doesn't do it. So I'm at a loss.
  6. Makosuke macrumors 603

    Aug 15, 2001
    The Cool Part of CA, USA
    Just to help narrow down what exactly is happening here:

    You will see the spinning colored wheel (aka SBOD) any time the mouse is held over the window of an application that hasn't responded to user input for a few seconds. So, for example, if Safari has completely hung, but I have a Finder window in the front of it right now, any time the mouse is over the Finder window, I will see a normal pointer, while if I hold it over the Safari window in the background, it will change to a SBOD. The same would happen in reverse if the Finder were hung and Safari was running normally.

    Now, the Dock almost never hangs unless the entire computer does, so the expected behavior would be for the mouse to change to a normal pointer when you move it over the Dock--I'm guessing that is what you're seeing, rather than the computer suddenly becoming responsive as soon as you put the mouse over the Dock.

    Taking this into account, can you confirm if it's JUST the Finder (for example) hanging, or if it really is everything?

    A second thing to try is to open up Activity Monitor (it's in the Utilities folder). It will show everything running on your Mac; you can sort the list by CPU use by clicking on the CPU column header. Applications that are not responding will show as red in that list.

    I would recommend opening up Activity Monitor and leaving it open at all times, with it's "floating CPU" window parked in the corner of your screen. The next time you see a hang, quickly look at two things: Do you see the CPU(s) working hard in the floating CPU window at that moment, and if you quickly switch to the window that shows a list of processes, which applications are showing as red, and what % do you see for them in the CPU column?

    This will help pin down what's going on.

    Final note: One of the most common causes of hangs in the OS is an I/O hang--if the computer is waiting for a disk to respond, EVERYTHING gets put on hold, and can result in widespread SBODs. If you have a network drive mounted--either from another computer in your house, a NAS, or maybe something remote like an iDisk--that could be the cause of hangs, particularly if the network drive takes a while to respond. Alternately, if there's something wrong with your hard drive--which causes it to periodically hang while it's recovering from an error--you would see exactly the behavior you're describing, and no amount of reinstalling would fix it apart from replacing the hard drive.
  7. JJP9398 macrumors member

    Jan 31, 2009
    I do have a NAS and 2 usb hard drives connected to my iMac. One hard drive is connected through my AEBS as well as the NAS, and one connected to the back of the iMac. I don't really use the hard drives so I will unplug them and see if that clears it up.
  8. Makosuke macrumors 603

    Aug 15, 2001
    The Cool Part of CA, USA
    That will be a good test, but to me it actually sounds VERY likely it's either the network-connected hard drive, or even a directly connected USB drive--either can go to sleep relatively quickly, and during the 3-5 seconds it takes a drive to spin back up you are pretty much guaranteed to see a SBOD hang if the program you're working in is trying to access something on the drive.

    Disconnecting them and seeing if it goes away is an easy test, but the other thing you can do if you're within earshot of the drives is listen carefully the next time you have a hang; if you hear a drive spinning up, and/or the click of the drive head un-parking just before the computer starts responding again, that pretty much confirms that a sleeping drive was the cause of the stall.

    I know this because I have a drive case with overly aggressive power management connected to my home server, and I see exactly such brief stalls every time it spins down when I'm using it.
  9. JJP9398 macrumors member

    Jan 31, 2009
    I unhooked the directly disconnected hard drives and left my NAS connected. It has been about 24 hours and I haven't had the rainbow wheel except once and that was when I was playing cityville on facebook. It only lasted about a second. I checked the activity monitor and it said that flash player was using something like 128% of the cpu.

    I think it might have been those usb hard drives. Overall I'm happy and I think I will only connect the hard drive when I need to use them. Thanks
  10. Makosuke macrumors 603

    Aug 15, 2001
    The Cool Part of CA, USA
    That particular stall was without question just Flash spazzing out, which it does occasionally. It's one of the many reasons it's developed a bad reputation.

    And it does sound like your issue was caused by the aggressive power management on your USB drive(s). Glad you got it figured out.
  11. ajalro thread starter macrumors newbie

    Apr 4, 2011
    On monday eveningm, After all possible test I called apple phone assistance
    they tell me to boot from snow leopard installation dvd and perform hard disk repair and permission repairing, I had already done it before but not from installation dvd but from my account utility disk.
    They told me to perform a VRAM reset too (I had done it before too without success for my problem)
    After the call I decided to completely uninstall flash player too

    Beginning from Tuesday I don't notice any problems... I don't know what to think... was the hd/permission repairing from dvd and not from account preference panel?? was the uninstallation of flash player? (but if so, why am I the only one to have this problem? I wasn't the only one to have flash player installed)

    Observing activity monitor I see that there is a process always among the first 3 position, sometimes in the first, about cpu%: it is google chrome helper related not to my account, but to the account of my girlfriend (in her desktop there 7-8 tab of google chrome open). what is this google chrome helper so heavy? (remember: flash player uninstalled)
  12. Makosuke macrumors 603

    Aug 15, 2001
    The Cool Part of CA, USA
    That's a bit tricky--unlike Safari, Firefox, and all other Mac browsers, which use the system-level Flash player, Chrome has Flash Player built into it; they do this, presumably, so they can keep it up to date on security patches.

    The Google Chrome Helper process you're seeing is almost without question Chrome's built-in Flash Player. In all likelihood, one or more of the tabs your girlfriend has open includes a poorly-coded Flash ad in it (they are EVERYWHERE), which will usually try to suck up one entire CPU core.

    This is why a lot of Mac users really hate Flash. The solution is to install Flashblock (or something similar--versions exist for Chrome, Safari, Firefox, etc); it will cause all Flash things embedded in web pages to NOT load by default--only if you click on them.

    Based on your description, it sounds like it's possible, likely even, that the problem you were seeing was also due to Flash ads (they can be in a background page, even) sucking up a lot of CPU and causing Safari hangs. In particular, if your girlfriend had an errant Flash something chewing up one CPU core, and you did as well, it's going to seriously bog down the entire computer (where usually Flash, being single-threaded, can only suck up a single CPU core, and will only cause the browser to act up).

    The easy test would be to try reinstalling Flash on your account and see if the problem returns. If it does, install Flashblock in your browser (and your girlfriend's) and see if it goes away--my money is on that fixing it.

    And if it does turn out to be Flash, as for why others aren't having the same problem, they are--you can find dozens of threads by people asking why their browser/computer is running so slowly, or the fans keep spinning up, etc, most of which are due to Flash. Installing Flashblock in Safari was the single biggest speed boost my daily computer use has ever gotten, personally. Again, there's a reason so many Mac users hate it. And in your case, if your girlfriend tends to leave tabs with Flash running in them open, you'd be seeing double the issues of most people, since the vast majority of users only have one login going at a time.

    Or it could be something completely different--possibly as simple as your computer being RAM starved--but reinstall Flash to test so you can rule that out first.
  13. ajalro thread starter macrumors newbie

    Apr 4, 2011
    hi Makosuke!
    thank you for your kind advice and sorry for my english

    I have a freeze of mine JUST NOW!
    I was selecting some files inside a folder with the arrows of the keyboard (I use the folder files visualization in coverflow) and it freezes!

    I have activity monitor open and I saw:
    quicklook help 75%
    google chrome helper 27%
    etc etc

    what do you feel to suggest me to try to solve my situation?
  14. Makosuke macrumors 603

    Aug 15, 2001
    The Cool Part of CA, USA
    Ok, I take that back, your problem apparently isn't Flash (although the Chrome-embedded player running on the other user isn't helping any).

    QuickLook Helper is generating the icon previews for the Coverflow view in the Finder; it's normal for it to use a lot of CPU to generate previews, especially if it's doing Coverflow, but not to hang the Finder.

    What I would guess is happening is one of three things: Either there's a file that's corrupt or Quicktime is otherwise having trouble reading, so Coverflow is hanging (and hanging the Finder with it) when it tries to draw the preview, there's a bad spot on disk, and that's causing a hang whenever the computer tries to read the flakey file, or you're short on RAM and you're getting into a swapping situation while the Finder tries to draw the previews.

    Take a look at the System Memory tab at the bottom of the Activity Monitor window; how much of it is showing as Free and Inactive, and how much is showing under the "Page outs" number and the "Swap used" number?
  15. ajalro thread starter macrumors newbie

    Apr 4, 2011
    Hi Makosuke,

    I think I've found the cause
    using activity monitor I found the process responsible
    I noticed that it starts every time I open a folder containing some video files not in apple native format, and it does the needed conversion from (ie) avi to mov to create the preview/thumbnails of the file
    every time I open divx folder this process starts and uses also 130%cpu! sometimes it goes without any problem, sometimes it freezes finder until I move the mouse on the app dock as I said

    I solve configuring the view option of this type of folder disabling the load of preview

    Until now it seems to work well

    what do you think about this?
  16. hayesk macrumors 65816

    May 20, 2003
    Hate to resurrect an old thread, but I'm seeing this on iChat video as well. For me, it seems to be anything that hardware-decodes video. Moving mouse to dock resurrects it.
  17. blubdog macrumors newbie

    Sep 28, 2011
    I've also had the problem ever since I purchased a new imac i7. My Macbook Pro has never had the problem.

    I was hoping that Lion would fix it, however I upgraded and I still have the same problem. I have noticed that it happens less often if I boot into 64bit mode, compared to the default 32bit boot.

    I am really stumped on this.
  18. Makosuke macrumors 603

    Aug 15, 2001
    The Cool Part of CA, USA
    Interestingly, after the attempted help I gave in this thread, my own i7 iMac developed a similar problem; programs that did some kind of hardware acceleration (common culprits were Flash, QT Player, Photoshop) would periodically hang the video until the window was in some way re-drawn--either by moving it (dragging the title bar) or switching to another application.

    It was a really weird issue, and was definitely restricted to just one account--my wife's account on the same machine with the same actions was fine. Also VERY repeatable--it would only take about 5-10 seconds of trying to get a problem app to misbehave.

    However, upgrading to Lion fixed it for me, so I never did get into in-depth troubleshooting.

    My general advice would be to try another account with no add-ons installed and see if it's okay. If not, maybe try a clean OS install and don't add any extras yet to see if that clears it up. If it is, then either do a manual transfer of settings to a fresh account until you find the one that's the problem, or start disabling any add-ons you use to see if that helps.
  19. blubdog macrumors newbie

    Sep 28, 2011
    Thanks for the reply, I'll try another account. But I'm not sure what you mean by "add-ons"? This is not limited to browsers, so browser extensions may not be the problem.

    I also have flash, photoshop, video players, and other programs installed, but I don't know if "add-ons" apply to them since the programs are either installed on the imac or not. BTW, I have all the same software installed on both my imac and my Macbook Pro, and the macbook has never had the problem.

    I had the problem today in Preview while trying to combine 3 PDF files by dragging and dropping pages from one preview window to another. Dragging would freeze over half the time before I could drop the page.
  20. Makosuke macrumors 603

    Aug 15, 2001
    The Cool Part of CA, USA
    I should have been more specific; when I said "add-ons" I meant any sorts of system modifications--new pref panes, menubar additions, system tweaks, etc. Things, basically, that run all the time and/or at a low level, and might theoretically mess something up.

    Also, just to check, is your stall only fixed by mousing over the Dock, as in the original question, or is it like mine in that moving the window in the hung program will immediately kick it back in? (I suspect that both problems might be the same, since a moving dock might adjust the window enough to un-hang the app, but I'm not sure.)

    You can pretty easily test if it's the same exact problem I was having by opening up a video (a Youtube video in Flash or anything in QT player), and using the position bar to skip around in the video for a bit. If it's the same as my problem, it will beachball and the video will hang within 5-10 seconds, guaranteed. Moving the window by dragging the title bar will immediately return it to normal.
  21. blubdog macrumors newbie

    Sep 28, 2011
    Thanks for the reply, I'll check for any 3rd party software that runs all the time or system mods.

    My stall is fixed by either mousing over the dock or grabbing the title bar and moving the window (or Command-TAB to another window and back, or switching to another desktop/space and back, and probably other things too).

    Looking at my System Preferences, I have 7 items in "Other":
    BetterTouchTool (which I can live without)
    Flash Player
    Flip4Mac WMV
    MacFUSE (which I no longer need)

    It could very well be one of those. I'd guess the media extensions are the most likely (flash/flip4mac/perian).

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