Mac Pro Causing modem slowness

Discussion in 'macOS' started by jacobhb, Oct 4, 2007.

  1. jacobhb macrumors newbie

    Jan 2, 2007
    My cable modem slows to near a halt when my Mac Pro is plugged into the network...

    So far comcast has come out and run a new line from the street to my home, put a fresh cable from the outside of the house to the inside, and also given me a new modem. All of this and my internet still crawls.

    So I have narrowed the problem down to my mac pro. When I run a direct connection from the modem to my MacPro and reset the modem, the internet will be blazing fast... then after about 2 minutes of use, the internet slow down SIGNIFICANTLY.

    So, I disconnect from my MacPro and plug into my iMac (reset modem), what do i find? There is no slow down at all.

    Now for the final test. I connect the modem to my router (airport extreme). Connect wirelessly with the iMac. Everything works fine. Now for the killer... I connect wirelessly with the macPro... BAM! Slowness almost immediately. Also, it won't go away until I reset my modem.

    Any ideas? The problem lies with the macPro... I am not sure what to do I am going crazy. I can't really talk to apple either... what am I suppose to say? My mac pro slows down my cable modem? They will just refer me to comcast and vise versa.

  2. apfhex macrumors 68030


    Aug 8, 2006
    Northern California
    Have you checked if your MP is sending and/or receiving lots of data for some unknown reason (look in Activity Monitor)? Have you tried connecting it while running a new user account? If you can't figure it out your last resort would probably be to reinstall OS X — if that doesn't fix it it must be a hardware defect, though I think that very unlikely.
  3. Sun Baked macrumors G5

    Sun Baked

    May 19, 2002
    Could be a corrupt preference file.

    You can try going to User/Library/Preferences and trashing the apple internet & airport preferences.

    Log out, and log back in and redo the internet configuration using system preferences.


    If that doesn't cure it, try making a new user and using it to see if the problem persists.
  4. jacobhb thread starter macrumors newbie

    Jan 2, 2007
    more problems

    So I made a new user but still have the same issues... You think the next step is a fresh install of the OS? Would be kind of lame with leopard so close to releasing....
  5. jacobhb thread starter macrumors newbie

    Jan 2, 2007
    Not sure if this has anything to do with it but I was looking at the activity monitor and it says
    Packets in: 21142
    Packets out: 30192

    Data reveived 3.23
    Data sent: 29.92 MB

    and all I am have open is firefox with this thread... and I am still doing 45.14 kb/s out...
  6. ebel3003 macrumors 6502a


    Jun 20, 2007
    "The Google"
    It looks to me like your Mac Pro is sending a constant stream of information somewhere. This constant upstream may be consuming all of your bandwidth (sending too much at once can slow down your internet connection). I would investigate what processes are running in the background.

    You may want to open Terminal and run the following command. This command will list all current internet connections.
    lsof -i
  7. jacobhb thread starter macrumors newbie

    Jan 2, 2007
    HA!!! I figured it out. Crash plan apparently was sucking all my bandwidth but there is no evidence of it open.... Kind of hillarious, kind of sad oh well.
  8. ebel3003 macrumors 6502a


    Jun 20, 2007
    "The Google"
    Good to hear. I'm surprised that it didn't show up, but as long as you figured it out.

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