Comment 90 for bug 630748

I have a Sony Vaio VPCF11S1E/B. Executing "lspci | grep -i network" produces:

02:00.0 Network controller: Intel Corporation Centrino Advanced-N 6200 (rev 35)

I am running the final release of 11.04 (all updates have been applied).

WiFi network functionality is unreliable, this is especially apparent when streaming (watching YouTube) or trying to download large files (anything around the 1GB mark). Everything starts off fine, but within minutes the download (or stream) will grind to a halt. I have tried stream and downloading the same files when I boot into Windows 7, and everything works without any problems. Also, running speedtest (http://www.speedtest.net/) the results are consistently 33% slower in 11.04 compared to Windows 7 or another laptop running 10.10 (friend's laptop). In 11.04 it "feels" like the downstream is capped at 20Mb/s.

This is a difficult problem to pin-point (for me) as initially I thought it may be the server(s) I'm downloading from or my ISP. However, after running a battery of downloads (torrents, podcasts, linux distros) and repeatedly watching YouTube clips on both Ubuntu 11.04 and Windows 7, I can confidently say that the problem lies within Ubuntu 11.04 (somewhere).

It's so annoying that I cannot continue using Ubuntu 11.04 as I can't even watch a 10 minute YouTube clip without the stream freezing within 2 or so minutes. I hope that a true fix will appear soon as I dread the thought of returning to Windows 7.