Can a cable modem cause my imac to become sluggish?

Discussion in 'iMac' started by p2burke, Sep 30, 2010.

  1. p2burke macrumors newbie

    Sep 28, 2010
    My iMac recently became sluggish. Suddenly I had problems with the computer pausing (beach ball). I upgraded my RAM from 1G to 2.5G. I have 98G free on my hard drive. I'm running 10.5.8. I messed with the disk utilities, got OnyX, and installed smcFanControl to run my fan at a higher speed. Finally, I began to wonder if it could be my internet connection. So I powered down and unplugged my ethernet cable. Now, no beach balling. Hmmm...

    Does anybody think maybe I need to replace my cable modem? It is older... but my MBP doesn't seem to be experiencing the problem. Granted, the MBP is newer... but everything is the same, except that it's running 2.2GHz as opposed to the iMac running 2GHz.

    Any thoughts?

    17 inch iMac 2GHz Intel Core 2 Duo
    Mac OS X v.10.5.8
    2.5 GB 667 MHz DDR2 SDRAM
  2. Spike88 macrumors 6502a

    Jan 25, 2010
    As a suggestion, reconfigure your system's MTU.

    For more details on MTU, surf:

    Note: See my next post for MTU Recommend/Set program details.

    If wondering, I changed my iMac's MTU size to 1492 (same as my ADSL Modem / Wireless "2Wire 1701 box" MTU "fixed value" size) and it works great. Much, much faster then allowing background "automatic" MTU task.


    To set MTU within my iMac 21.5" (that can also be used for a MBP), I used a free MTU size Discovery / Set utility. With this tool (saved in my iMac's Applications - Utility folder), I manually set its MTU on all ports (ethernet, wireless, firewire, etc.) only once. Set it once and its done.

    This script can be found at:

    Note: Click on its "Download the Set MTU 0.2 script application (zip)" text - to obtain the MTU script file.

    And yes, this script works great on mid-2010 21.5" iMacs using SL as well.

    Hope this helps...

  3. RRmalvado macrumors 6502

    May 27, 2010
    Have you tried powering off the cable modem for a couple of minutes and then power it on again?
  4. p2burke thread starter macrumors newbie

    Sep 28, 2010
    Thanks for the quick responses!

    Thanks Spike88, after trying a couple of different settings, I think I found one that seems to be working! (1400). I'll let you know if the fix holds up!

    Thanks RRmalvado, yes, I definitely tried that. Appreciate it though!
  5. p2burke thread starter macrumors newbie

    Sep 28, 2010
    The Beachball is back!

    Well, it was great while it lasted...

    The beachball is back!

    I'm going to try a few more settings. This is frustrating, but thanks for the help.:confused:
  6. RRmalvado macrumors 6502

    May 27, 2010
    Can you try disconnecting the ethernet connection and using wireless?
  7. p2burke thread starter macrumors newbie

    Sep 28, 2010
    a clean reinstall took 24 hours...

    well, i tried just about everything... and out of sheer frustration, i decided a clean reinstall was the only thing left to try. but the reinstall took 24 hours! umm, guys, help me out here... what's going on? and it's running slower than ever!!!:eek:
  8. wirelessness macrumors 6502

    Jun 20, 2010
    Sounds like your hard drive could be going bad. It should not take that long to install the OS.

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