Does Time Machine slow down your system?

Discussion in 'Mac Basics and Help' started by cleo, Mar 7, 2009.

  1. macrumors 65816


    Jan 21, 2002
    Tampa Bay Area, FL, USA
    I've noticed lately that when a backup is occurring, my system gets really slow. Like, so slow that I sometimes wind up canceling the backup out of frustration. Is this normal? (I have a 2.4 GHz Core 2 Duo MBP, 4 GB RAM)

    At the same time, the backup drive seems to have gotten rather noisy during backups. It has a second partition that I use for recording/watching TV (with an EyeTV), and it's quiet as a mouse.

    What gives?
  2. macrumors 6502


    Dec 5, 2008
    I've never noticed any slowdowns on my mini while Time Machine is doing a backup and my drive is virtually silent (Seagate FreeAgent 250GB) while active.

    I don't have any experience using TM on a MBP however so I wouldn't really know.
  3. Administrator

    Doctor Q

    Staff Member

    Sep 19, 2002
    Q Division, Los Angeles
    I notice no slowdown at all, even on my old Power Mac G5. I can't explain why some people "feel" backups in progress as a performance hit. You aren't the first to say so.

    Suggestion: Using System Preferences -> Time Machine, turn on "Show Time Machine Status in the menuu bar", if it's not already on. Then pay close attention the next few times, to see if the slowdown happens only when the backup is starting or ending, or if it's slow all the time when a backup is in progress.

    Also, are you frequently changing large files? For most people, there isn't much data for Time Machine to copy since the previous backup, but maybe you are unusual and make it work harder.
  4. macrumors member

    Jul 15, 2008
    I feel no slow down at all on my UMBP (2.4GHz, 2GB RAM, 320GB 7200RPM harddrive) i backup via USB on a 1TB external harddrive - think it's a Western Digital. I'm always finding out that it is doing backup for random reasons. Like if i for example are looking at the clock and then see the Time Machine icon is spinning around.
  5. macrumors Core


    Feb 9, 2008
    San Jose (CA)
    From what I can tell, Time Machine depends on Spotlight index files, so when you back it needs to access and "calculate" the files needed to backup which may result in the slowdowns. When back up, I have slowdowns, but not as severe as to cause my computer to become unusable in any way..
  6. macrumors 6502a

    Oct 28, 2007
    Leeds, UK
    my time machine never makes my system run slow. macbook with a 2.5" usb external
  7. Administrator

    Doctor Q

    Staff Member

    Sep 19, 2002
    Q Division, Los Angeles
    I thought it was smarter than that, and kept a queue of changed files at the file-system level, updated every time a file changed, so it didn't have to search or look for files. That way, it already has the list of pending files when the time comes.
  8. macrumors 68000


    Jan 21, 2008
    Melbourne, FL
    I do check the Activity Monitor sometimes just to see what is going on but I can't say I've seen a lot of extra activity devoted to Time Machine. I do sometimes notice a momentary slowdown as my time capsule mounts but once it is running it evens out. Of course when Time Machine loses its way, all bets are off on what it is going to need to do to find its way home. Usually means an extended visit that can involve spotlight.
  9. macrumors newbie

    Mar 18, 2013
    I know this is an older post but I've just started using Time Machine and see a real slow down when it's running. I don't know, if this is a factor but at the moment it's backing up 4Gb of photos. Each file is about 20Mb. Any suggestions what to do about this, please?
  10. macrumors newbie

    Aug 10, 2013
    Eureka! Fix for Time Machine slowing down system

    I had a late-2008 MBP which was REALLY suffering when Time Machine started a backup. Symptoms included:
    1. Mouse pointer very jerky when moving mouse.
    2. Bluetooth keyboard disconnecting.
    3. When connected, many spaces or extra characters when typing.

    The symptoms seemed to worsen over time. I'd thought it got worse when upgrading to Snow Leopard, then Lion, then Mountain Lion.

    What seems to have fixed this is to rebuild the spotlight metadata. From the terminal command line:
    sudo mdutil -E /

    (You will need to enter the administrator password.)

    What then happens is that the Spotlight index is rebuilt. This takes a couple of hours. However, it seems also to have helped with the system slowdown when TM is backing up. I don't understand why this helped on my system, but am posting this in case it helps others.
  11. macrumors G3

    Apple fanboy

    Feb 21, 2012
    Behind the Lens, UK
    I use a Time capsule, and other than I can hear the hard drive spinning up and see the Time Machine back up symbol, I would never know.
    How is the HD connected? I use Ethernet cable as it's in the same room as my iMac.

Share This Page