Huge Internet slowdown after updates?

Discussion in 'iMac' started by Darl Bundren, Sep 30, 2010.

  1. Darl Bundren macrumors newbie

    Oct 25, 2009
    Hey, all. I have an i5 iMac, and I am very pleased with it. However, for the last two or three days the Internet has been stupendously slow. On my netbook upstairs (hardlined in) the Internet is as fast as it should be from my cable modem.

    A couple of days ago, I seem to remember my computer updating as I went to shut it down--I installed the updates without really checking what they were.

    Three questions: How can I navigate to my history to figure out what the updates were?

    How can I undo any updates that have adversely affected my computer?

    And, would software updates have that drastic of an effect on Internet speed?

    As always, thanks.
  2. Spike88 macrumors 6502a

    Jan 25, 2010
    Some applications modify the system's MTU - without notice.

    With this in mind, do reconfigure your system's MTU.

    For more details on MTU, surf:

    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...


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