I've searched the forums for some info but didn't find anything that helped, so I'm making this post. I installed an Airport Extreme card into my Mac Pro today. Here are the card details: Card Type: AirPort Extreme (0x14E4, 0x88) Firmware Version: Broadcom BCM43xx 1.0 (126.96.36.199.1) Locale: FCC Country Code: X0 Supported PHY Modes: 802.11 a/b/g/n I made sure the antennas were connected to the card properly before hand. I get full signal across my house from the router, which is great, but when I go to speed test, that's the problem. On my MacBook Air and on the Mac Pro with ethernet plugged in, I get 1900kbps-2400kbps, consistently every time. This is in file downloads and on speedtest.com. Now, on the Mac Pro with this card, I get anywhere from 300kbps-1100kbps my speed is cut by over half. I'm using an Apple Airport Base Station. I've experimented with the multicast rate, the broadcast mode (a/b/g/n), and several other settings I could think of. What can I do to fix this problem? I need faster network speeds than this, it's very frustrating.