Slow WiFi with External Display

Discussion in 'MacBook Air' started by lehman310, Sep 2, 2014.

  1. lehman310, Sep 2, 2014
    Last edited: Sep 2, 2014

    lehman310 macrumors member

    Mar 10, 2009
    I am having a strange issue with my Mid 2012 Macbook Air. Whenever I connect my external display via Thunderbolt to DVI adapter, my WiFi speed goes from 45mbps to <0.5mbps. The same issue does not occur when I use Thunderbolt to HDMI to connect to TV. In addition to this, I get around 70mbps from the same location on my iPad (right next to router on 100mbps connection) so I am wondering if my WiFi card is going bad or if theres something I can do on the software end of things.


    Edit: Ive changed the external display resolution and I can get 25mbps but its still not what I get without display connected.
  2. alphaod macrumors Core


    Feb 9, 2008
    Sounds like the adapter you're using isn't shielded correctly and perhaps causing interference? I have an adapter that I bought that did this. I would cause my WiFi, Bluetooth, and Logitech receiver RF to all drop.

    Unplugging it immediately resolved the issue.
  3. Boyd01 macrumors 68040


    Feb 21, 2012
    New Jersey Pine Barrens
    I use a DVI adapter with an old 23" Cinema display on my 2013 MBA every day. It has no effect on wifi - I get about 60MB/s copying files on the LAN with 802.11ac.

    I would try another adapter and another display and see what happens.

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