The latest is I removed network-manager and use wicd to "manage" the network. I think it's better than before but still iffy. I know it sounds very not scientific but that's me because I am not scientific. Basically the Wifi support for Ubuntu 15.04 has been terrible ... for me if not for everybody. I think this article kind of resembles what I experience. In the last post it says "removed network-manager package, and used netctl for managing wifi, and the problem is gone" I am not wizard so I have a difficult time figuring how to install netctl in Ubuntu GNOME. In the end I gave up and installed WICD. At some point it got stuck at 1Mb/s but if I wasn't dreaming I think it did connect at 36Mb/s. It now connects at 11Mb/s. I am not exactly complaining as long as it is double digit. All in all it's iffy. Not good.
Before I did all the above I also ordered a card that supposedly works out of the box on 15.04, I will find out soon. It's a b/g/n card with max rate at 300Mb/s. I doubt I can reach that but I would be thoroughly thrilled if it reaches 50Mb/s, the top speed of the router.
I guess I was happy too soon. The connection drops and wouldn't reconnect. And when connected the rate drops to 1Mb/s, like modem or something.
I am counting on my new card now.
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Basically I have very slow connection rate, from 1Mb/s to 11Mb/s or mostly no connection at all with this combination. Prior to 15.04, 14.04 LTS or 14.10, the WiFi connection has been pretty stable and the quality has been satisfactory, I don't think I ever reach the 54Mb/s rate but at least I got some where at 20Mb/s. (My WiFi connected MacBook Pro get more than 50Mb/s and noticeably faster)
I thought ndiswrapper would be the solution. Alas it was, only momentarily.
So the struggle continues.
PS: I should have left it at 14.10 because seemingly the WiFi is solid and I have no random reboots like I have had on 14.04 LTS
PPS: In addition to the WiFi problem, I have had a few random reboots in 15.04 already.
PPPS: Shotwell unequivocally continues to suck. Part of the library continues to disappear, the import is still very very problematic. I wonder does anybody ever get it to work like normally? Part of my motivation to get on board to 15.04 was to see if Shotwell would work better. Now I know.
PPPPS: So in a nutshell, the 15.04 offers no benefits to me.
NOTES TO SELF:
http://ubuntuforums.org/showthread.php?t=1433233 back in 2010
https://ubuntu-mate.community/t/solved-ralink-rt2561-rt61-wifi-problem-15-04-beta2/828/7 this is where I got the idea. Unfortunately just like one of them, the ndiswrapper doesn't quite work for me, it drops connection just like the Linux driver installed originally.
http://us.edimax.com/edimax/download/download/data/edimax/us/download/product/home_legacy_products/home_legacy_wireless_adapters/ew-7128g/ manufacturer's support site
http://www.mediatek.com/en/downloads1/downloads/rt2501pcimpcicbrt61rt2561rt2561srt2661/
http://www.reddit.com/r/Ubuntu/comments/30ish0/ubuntu_14041504_uefi_restartpower_off_problem/