Processes fast up until 1GB of RAM usage, then slow

Discussion in 'macOS' started by bilts, Jan 27, 2012.

  1. bilts macrumors newbie

    Joined:
    Jan 27, 2012
    #1
    This one is a little weird. I've been searching for answers for a while but haven't had any luck.

    I have a MacBook Pro with 8GB of RAM and Snow Leopard.

    I've noticed that applications get slow when they surpass 1GB of RAM usage, regardless of how much total RAM is available. I notice it most frequently with Firefox. Everything is fast, then suddenly a page will stutter when I scroll. I'll look at the "Real Mem" in the Activity Monitor, and it'll be within a few MB of 1GB.

    I'm convinced this is not entirely a Firefox thing, though, but it's most noticeable there. I see it with VirtualBox as well and various Java processes that have more than 1GB allocated to the JVM.

    Oddly, it causes a CPU spike, not a disk usage spike as I'd expect with virtual memory churn.

    Thoughts? Is there some memory parameter I can set? Has anyone else seen this?
     
  2. parapup macrumors 65816

    parapup

    Joined:
    Oct 31, 2006
    #2
    Memory usage seems like it is just a coincidence. Your real issue at least with Firefox stutter is CPU usage - I have seen that if you have multiple tabs in FF that are all consuming CPU or there is another app that is taking up CPU (VM etc) then FF will stutter.

    I haven't found any solution to that apart from limiting CPU usage by running less CPU hogs at once.
     
  3. bilts thread starter macrumors newbie

    Joined:
    Jan 27, 2012
    #3
    I'm convinced it has something to do with that exact amount of memory.

    I've paid very close attention to this. The moment I notice stuttering scrolling, I look at the memory usage. It is always close to 1GB. Not 1.2GB or 900MB, more like 1.02 GB. I've done this easily half a dozen times, and it's far too predictable to be a coincidence.

    At first I assumed it was something with Firefox, that it had some garbage collection that started churning at 1GB, but like I said, I've noticed it with other applications as well.

    Apart from being the OS or some setting therein, my only other plausible suspect is Symantec AntiVirus, but I have live scanning disabled, so that seems unlikely.
     
  4. parapup, Jan 27, 2012
    Last edited: Jan 27, 2012

    parapup macrumors 65816

    parapup

    Joined:
    Oct 31, 2006
    #4
    Hmm all bets off - Symantec Antivirus! I had to reinstall OS X last time I tried installing our corporate copy in order to get on VPN. Try uninstalling it and see I guess.

    Also : If Firefox up2date? I know there were some pretty bad memory bugs fixed recently. The other thing to check is that do you always have high CPU when the stutter occurs (I bet you do since you have 8GB RAM most of it free. There is no other reason for stutter than CPU usage, if your machine isn't swapping.)
     
  5. bilts thread starter macrumors newbie

    Joined:
    Jan 27, 2012
    #5
    Firefox is up to date (v9.0.1). This has been happening for a long time, though. At least since v4.

    Unfortunately uninstalling AV is the one option I don't have, since this is a work machine. But like I said, live scanning is disabled. I could see it being a problem despite that, but uninstalling isn't a fix for me.

    As a developer with many tools running at once, I do sometimes approach 8GB of memory usage, but this happens with much fewer than 8GB used. I can't say for certain whether there's a CPU spike all of the time. I'll have to pay more attention to that aspect.

    So, there's no magic "don't choke at 1GB" command? No one else has reported this issue? Weird.
     
  6. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #6
    If you want to improve your performance, uninstall Symantec immediately. You don't need any 3rd party antivirus app to keep your Mac malware-free. Macs are not immune to malware, but no true viruses exist in the wild that can run on Mac OS X, and there never have been any since it was released 10 years ago. You cannot infect your Mac simply by visiting a website, unzipping a file, opening an email attachment or joining a network. The only malware in the wild that can affect Mac OS X is a handful of trojans, which cannot infect your Mac unless you actively install them, and they can be easily avoided with some basic education, common sense and care in what software you install. Also, Mac OS X Snow Leopard and Lion have anti-malware protection built in, further reducing the need for 3rd party antivirus apps.
    If you're forced to use AV, use ClamXav. It is one of the best choices, since it isn't a resource hog, detects both Mac and Windows malware and doesn't run with elevated privileges. You can run scans when you choose, rather than leaving it running all the time, slowing your system. ClamXav has a Sentry feature which, if enabled, will use significant system resources to constantly scan. Disable the Sentry feature. You don't need it. Also, when you first install ClamXav, as with many antivirus apps, it may perform an initial full system scan, which will consume resources. Once the initial scan is complete, periodic on-demand scans will have much lower demands on resources.

    No, because there's no magic "choke at 1GB" issue. You're misreading the symptoms. Your system will not choke because of 1GB of RAM usage. Not ever. There are other factors at work. Launch Activity Monitor and change "My Processes" at the top to "All Processes", then click on the CPU column heading once or twice, so the arrow points downward (highest values on top). Then look to see what may be consuming system resources.
     
  7. damson34 macrumors 6502

    Joined:
    Jul 18, 2002
    Location:
    Houston, TX
    #7
    Did you even read his actual post? He said uninstalling Norton is not an option since it is a company computer, not his personal computer.
     
  8. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #8
    Did you even read all of my post? Yes, I read all of the OP, and the post I responded to about uninstalling hadn't yet mentioned the work computer. Norton can be disabled without uninstalling it, and ClamXav can be used instead.
     
  9. bilts thread starter macrumors newbie

    Joined:
    Jan 27, 2012
    #9
    Uninstalling or disabling Norton is not an option. I have disabled the live scan, which is as much as I can do. Installing a second AV on top of the first is asking for trouble in terms of system resources. I could see this being a problem with the AV, though I'd appreciate something more concrete than a hunch. It's been happening long enough that someone else should have seen it.

    I always keep System Monitor open and showing all processes (I'm a developer, so it's useful having it in the dock). In these cases, the only process eating resources is the one with 1GB of memory usage, e.g. Firefox or VirtualBox. Ordinarily I'd suspect the individual process, but it happens to multiple distinct programs at the 1GB mark.
     
  10. damson34 macrumors 6502

    Joined:
    Jul 18, 2002
    Location:
    Houston, TX
    #10
    Thats his post directly above your post, that specifically states and I quote again "Unfortunately uninstalling AV is the one option I don't have, since this is a work machine."

    So Yes I read your post, and his post, and the reply to my post that you made. Just posting links about information isn't appropriate in every circumstance but Ive noticed thats the thing you like to do in posts.
     

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