I'm driving myself crazy trying to figure out why my wifi speeds vary so greatly across devices. First, my setup: I have Time Warner internet rated for 100 Mbps An Airport Extreme in my living room (A1143 2nd Gen) is connected to the modem via ethernet. I have a Mac Mini connected to this Extreme via Ethernet as well. Wifi does not travel well in my house, so I run ethernet from the Extreme to a 200Mb power line adaptor (this model: http://www.amazon.com/gp/product/B00FF8ZRPU/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1) In a back room, I run ethernet out of the same model power line adaptor into a 1st gen A1143 Airport Extreme. Although the power outlets using the power line adaptors are on the same circuit, there's usually a pretty big drop in speed from the front of the house to the back of the house. My house is old and the wiring is terrible, so I figure that's to be expected. That's not my problem here. My problem is that everything connecting to my airport in the front room is connecting at drastically different speeds. Just now, when I run Speedtest on my Mini that's connected to the Airport Extreme via ethernet, I get a download speed of 106 Mbps When I run the test on my mid-2011 Macbook Air using wifi, I get a speed of 54Mbps When I run the test on my iPhone 6 using wifi, I get a speed of 27.4Mbps I'm running the Macbook and iPhone tests in my living room, 8 feet from the Mac Mini/Airport Extreme setup Both of my Airport Extremes are set up to "Create a New Wireless Network" using the same network name and WPA2 security. Radio mode for both Airports used to be 802.11n (802.11 b/g compatible), but I first switched both to 802.11n only (2.4GHz) and then to 802.11n only (5GHz), but there was no change in wireless speed. Might the solution be as simple as my having outdated Airport Extremes? Even so, I'm at a loss as to why my iPhone consistently shows a lower wifi speed than my laptop. If it makes a difference, I have quite a few devices hooked up to wifi at any one time: 2 iPad 1's, a mini retina iPad, iPhone 6, iPhone 5s, a very old mac mini (different than the one in my living room), an apple TV, wireless printer, and a few Sonos devices. Any leads are most appreciated.