I have seen many posts about this with lots of different problems. Here's mine. I upgraded from the 7260N card, looking to take advantage of 5GHz connectivity.
Recently installed the 7260AC card in my Yoga 2 Pro. Works great @ 2.4GHz. That means ~50MB/s download. Switching to 5 GHz yields slightly higher (maybe 55MB/s)....for a little while, then the connection drops and resets. Again and again and again, just about every 5 seconds. Why? This makes Internet use impossible
Compared to another Dell laptop (Intel Centrino Advanced-N 6205) in the same house, at the same physical location, gets steady 50MB/s at 2.4GHz and 95-100MB/s @ 5GHz.
I have installed the 17.0.5.8 driver and am frustrated. What am I doing wrong? Should I consider a different card? I pay for 100MB/s speeds and want to be able to make use of it.