Realtek RTL8723AE wifi regression: badly slow compared to other OSs

[Enrico]

My wireless card "Realtek RTL8723AE PCIe Wireless Network Adapter" doesn't work fine on 15.04. It works pretty fine on 14.10 and previous versions, but it's unstable on 15.04 and the most of times it can't connect to my WiFi network. Sometimes I can solve deleting the network from "Edit connections", but when i can connect the connection is unstable and really slow (40-50 kb/s in download).
The same wifi card with the same wifi networks worked fine until I've updated to Ubuntu 15.04 so i can suppose that it's a Vivid's bug

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: linux-image-3.19.0-7-generic 3.19.0-7.7
ProcVersionSignature: Ubuntu 3.19.0-7.7-generic 3.19.0
Uname: Linux 3.19.0-7-generic x86_64
ApportVersion: 2.16.2-0ubuntu2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: enrico 1890 F.... pulseaudio
 /dev/snd/controlC1: enrico 1890 F.... pulseaudio
CurrentDesktop: Unity
Date: Tue Mar 10 20:49:22 2015
InstallationDate: Installed on 2015-02-15 (23 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
MachineType: TOSHIBA SATELLITE C855-2J5
ProcFB: 0 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-7-generic.efi.signed root=UUID=0a5b817b-470d-4af2-9e2b-e621bd3d341f ro quiet splash vt.handoff=7
SourcePackage: linux
UpgradeStatus: Upgraded to vivid on 2015-03-01 (9 days ago)
dmi.bios.date: 10/01/2013
dmi.bios.vendor: Insyde Corp.
dmi.bios.version: 6.80
dmi.board.asset.tag: Type2 - Board Asset Tag
dmi.board.name: PLCSF8
dmi.board.vendor: Intel
dmi.board.version: Type2 - Board Version
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: OEM Chassis Manufacturer
dmi.chassis.version: OEM Chassis Version
dmi.modalias: dmi:bvnInsydeCorp.:bvr6.80:bd10/01/2013:svnTOSHIBA:pnSATELLITEC855-2J5:pvrPSCBYE-04F00RIT:rvnIntel:rnPLCSF8:rvrType2-BoardVersion:cvnOEMChassisManufacturer:ct10:cvrOEMChassisVersion:
dmi.product.name: SATELLITE C855-2J5
dmi.product.version: PSCBYE-04F00RIT
dmi.sys.vendor: TOSHIBA

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.0 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.0-rc3-vivid/

[Enrico (enricobe)]

Hi. I have installed the lastest Kernel (4 RC3) and the connection seems to work fine, it always connects, but the speed is really slow!
I've tried to download the Ubuntu ISO from the website and the OpenOffice package and the network has never gone over 90 kb/s. With a USB network adapter i reach 600 kb/s and on Windows i go up to 800 kb/s

[Joseph Salisbury (jsalisbury)]

Do you also see the same slowness if you boot back into a Utopic kernel(3.16 based) while running Vivid?

[Enrico (enricobe)]

Yes, it is slow with kernel 3.16, too.

[Joseph Salisbury (jsalisbury)]

So it sounds like the following is true:

14.10(3.16): Stable bug always slow.
15.05(3.19): Unstable and slow.
Mainline kernel(4.0-rc3) stable again, but still slow.

[Enrico (enricobe)]

Yes, but I've not tried with 14.10. I've tested it on 15.10 with kernel 3.16.

We can say:
15.04(3.16): Stable bug always slow.
15.04(3.19): Unstable and slow.
15.04(4.0-rc3) stable again, but still slow.

[Joseph Salisbury (jsalisbury)]

In the bug description you say that it was working fine in 14.10. Was it also slow in 14.10, which has the 3.16 kernel?

[Enrico (enricobe)]

Hello.
Today i've done some more accurate tests.

I've downloaded the ISO from UBUNTU.COM. Same ISO, same version (amd64), same WiFi network with same connected devices, i've tired to download it twice from each kernel, almost 5 mins in download before record the speed.

---------
Windows 8.1:
starts at 1Mb/s and then it goes stable to 800-850 kb/s
---------
Ubuntu 15.04 with Kernel 4.0 RC3:
starts at 90 kb/s and then goes up to 190 (stable). Some times it speed up to 400 kb/s but it's not stable, e.g. It downloads at 400 kb/s, then stops for 2-3 seconds and downloads again. I think that the medium speed is always about 190 kb/s...
---------
Ubuntu 15.04 with Kernel 3.19
It often doesn't connects to the wifi. When it connects the speed is stable to 100 kb/s
---------
Ubuntu 15.04 with kernel 3.16
It seems to connect every time, and it's a little faster than 3.19. It goes stable at 110-120 kb/s
---------
Ubuntu 14.10 (LiveDVD) with kernel 3.16
Works live in 15.04 with kernel 3.16
-------------

So the Kernel 4 seems a little better than the others. 3.19 on Ubuntu 15.04 is the worst because it has connection problems and slow speed

[Enrico (enricobe)]

The speed is good with Manjaro Linux, so I suppose that it's a Ubuntu's bug

[Enrico (enricobe)]

Hello,
I found the solution to the problem thank to a post on a blog of which I don't remeber the name. The solution is disable the the "WMM (Wi-fi Multi-Media)" from the router. This option can be found on the QoS menù of the router.

I'm not sure if it can be considered a bug of Ubuntu...

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu Vivid) because there has been no activity for 60 days.]

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

[Brad Figg (brad-figg)]

This change was made by a bot.

[Brad Figg (brad-figg)]

This change was made by a bot.