New iMac throttling wifi speeds?

Discussion in 'iMac' started by bpetruzzo, Feb 16, 2011.

  1. bpetruzzo macrumors regular

    Oct 22, 2005
    I have been pulling my hair out over this.

    I have a Macbook Pro less than 5 feet from my new iMac and it's speed testing at nearly 20mbps. My iMac, on the other hand, is struggling to hit 5mbps. I have closed everything that I know to close. But it's had no effect.

    The iMac is a kind of software clone of an older computer that it replaced. I'm wondering if there might be some software I installed on the old computer somewhere along the way that might be causing me problems.

    Any ideas?
  2. satcomer, Feb 16, 2011
    Last edited: Feb 16, 2011

    satcomer macrumors 603


    Feb 19, 2008
    The Finger Lakes Region
    How getting an external drive and clone it. Then do a Fresh install of Snow Leopard. Then at then end of the install (after you updated to all the Software Updates) and use Migration Assistant (/Applications/Utilities/Migration Assistant) and get your data of the cloned drive. After all that do a new clone or use Time Machine on that external.

    I feel with the Fresh Install will fix your wireless issues.

    If you don't want to do that then follow these steps:

    1. Open System Preferences->Network pane turn off the Airport card!!!
    2. Navigate to the folder /YourHardDrive/Library/Preferences/SystemConfiguration/ and move all the files to your desktop.
    3. Immediately reboot so OS X can rebuild those drivers. It will take a minute on Startup while it re-writes those files.
    4. Go back into System Preferences->Network pane and turn the Airport card back on.

    On more thing. In System Preferences->Network pane look at the top of the pane for the "Automatic" drop-down. Create a new custom named Location (it will act just like Automatic) and at the bottom of the pane (after changing the Location) and click the 'Apply" to save that new Location. Then rejoin the wireless network.
  3. robgendreau macrumors 68040

    Jul 13, 2008
    I had a similar problem with a new iMac I migrated.

    Never found out exactly why it did it, but I had to essentially give it a new network identity. Just refreshing the DHCP lease wasn't enough, I made a new location etc etc as if I were hooking it up for the first time. Then the problem disappeared.

  4. Troy47 macrumors newbie

    Apr 7, 2010
    My brand new 27 did the same thing,15 megs for my macbook, 3 or 4 for the imac. I returned mine.
  5. jlyanks85 macrumors 6502a

    Jan 3, 2008
    With wifi on my imac I was having really fast web browsing speeds, but d/ling stuff like movies and tv shows on iTunes, it would take forever to d/l.

    Then I started using a ethernet cable to plug right into the router, and d/ling movies on itunes has a HUGE increase in speed. Don't know why that is, but it's fine by me.
  6. jlyanks85 macrumors 6502a

    Jan 3, 2008
    I must of jinxed myself, because I d/led a movie that went smoothly. Now I bought a season of a TV series and one episode is taking a eternity to d/l.

    Don't understand why this is happening.
  7. flipster macrumors 6502a

    Mar 14, 2010
    Hmm, if anyone has a way that could make loading times faster, post it!

    I really want to connect my computer to ethernet though.

    Ethernet computer gets 24 mbps

    Wireless computer gets 16 mbps.

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