Wifi slow on Intel Corporation Centrino Ultimate-N 6300

[Valentin Crone]

On Intel Corporation Centrino Ultimate-N 6300 who use iwlwifi, the Wifi goes approximately (in my home) to 15MB/s in up and down on Windows 7, but it goes only to 5 - 6MB/s down, and 1 - 3MB/s up on Linux.

Before Ubuntu 11.04 → It was slow.
After Ubuntu 11.04 → It was slow.

On Ubuntu 11.04 (Only for test): The down speed is approximately 11MB/s and the up speed is approximately: 6 - 8MB/s

The driver contain a regression for speed performance.

Currently I use Ubuntu 14.04 LTS with Linux 3.18.1 (Vivid package) but the speed is already slow.
The range of the card is reduced, and I take sometimes 2 - 5min to discover a network.

Connection/disconnection to an other network can make a bug were the fastest way to change network is to disable/enable the card (if it works), or reboot the computer.

It make this card absolutely not reliable because of the driver on Linux.

---
ApportVersion: 2.14.1-0ubuntu3.11
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: valentin 4266 F.... pulseaudio
 /dev/snd/controlC0: valentin 4266 F.... pulseaudio
CurrentDesktop: Unity
DistroRelease: Ubuntu 14.04
InstallationDate: Installed on 2014-11-24 (245 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
MachineType: Dell Inc. Latitude E6540
Package: linux (not installed)
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-46-generic root=UUID=83928b5e-863a-4f13-98b2-f288f6a095dc ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 3.13.0-46.79-generic 3.13.11-ckt15
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-46-generic N/A
 linux-backports-modules-3.13.0-46-generic N/A
 linux-firmware 1.127.14
StagingDrivers: zram
Tags: trusty staging
Uname: Linux 3.13.0-46-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
_MarkForUpload: True
dmi.bios.date: 05/19/2015
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A15
dmi.board.name: 0725FP
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 9
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA15:bd05/19/2015:svnDellInc.:pnLatitudeE6540:pvr01:rvnDellInc.:rn0725FP:rvrA00:cvnDellInc.:ct9:cvr:
dmi.product.name: Latitude E6540
dmi.product.version: 01
dmi.sys.vendor: Dell Inc.

[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 v4.2 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'.

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/v4.2-rc2-unstable/

[Valentin Crone (va-crone)]

Hello,

I have tested for the 4.2 rc2 on my laptop: Max 7MB/s down, and 2MB/s up.
15MB/s on Windows 7 for up and down.

(1m max between the laptop and the AP for the test)

I have set the bug as "Confirmed",
Thank you

[penalvch (penalvch)]

Valentin Crone, please execute the following command, as it will automatically gather debugging information, in a terminal:
apport-collect 1471794
When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[Valentin Crone (va-crone)]

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[Valentin Crone (va-crone)]

OK, informations collected.
Now you can set the bug as confirmed?

And thank you for the doc :)

[penalvch (penalvch)]

Valentin Crone, could you please test the latest mainline kernel (4.2-rc4) and advise to the results?

[Valentin Crone (va-crone)]

I have ever tested this version, the bug is always here.

[penalvch (penalvch)]

Valentin Crone, could you please provide the missing information following https://wiki.ubuntu.com/Kernel/LinuxWireless ?

[Valentin Crone (va-crone)]

Hello,
1)
Full computer model name: DELL Latitude E6540
With:
16GB of RAM
120GB SSD
Intel Core I5 4200M
Intel Corporation Centrino Ultimate-N 6300
AMD Radeon 8790M (Mars XTX)

2)
BIOS: A15, latest, this not correct anything for the Wireless, but this fix many bugs like keyboard or usb disconnection.

3)
AP: 01:00.0 Network controller: Qualcomm Atheros AR93xx Wireless Network Adapter (rev 01)
TP-Link TL-WDN4800 ( http://www.tp-link.fr/products/details/?categoryid=1683&model=TL-WDN4800 )
The AP are 2 servers on Ubuntu 12.04.5 LTS 64bits, but I have no problems with others devices, and this computer have Wireless problems with all others AP.

Connection type: 802.11n (Yes, the problem is the same with others types)
Channel: 1 (The problem is the same with other channels)

Wireless environnement:
DS Parameter set: channel 1
DS Parameter set: channel 1

(My 2 AP, one is approximately as 1m, and the second is 2 floors upper)

Encryption: WPA2-PSK
Nope, changing encryption don't change anything.

QoS: Nope, I have disabled this because it don't change anything for the AP, it's not a problem for today use with others computer.

Beacon time: Default, 100
Changing beacon time: Not tested.

Firewall: Yes, but not on the wireless interface, it's on the ethernet card where internet arrive.
Nope, I don't disable the Firewall of my server, but this will close the network.
The AP is on a bridge with 2 eth, and all packet who have source br0 are accepted for input and forward.

Frequency: 2.4Ghz
Not tested in 5Ghz because too many card are not compatibles.

4)
With an other device, the AP have no problems.

5) 1 - 2m for the tests

6) 0, this is directly next to the AP wlan card

7) Yes

8) It seem that Natty have better performances, but it's really not perfect

14)
Firmware version:
[ 2.33682] iwlwifi 0000:03:00.0: loaded firmware version 9.221.4.1 build 25532 op_mode iwldvm

15) Ndiswrapper not tested, because for the same computer, Windows 7 64bits have a really good speed. (Approximately 15MB/s up and down on my AP)

[Valentin Crone (va-crone)]

Hello,
This bug is always incomplete or it can be considered as confirmed?
Thank you :)

[dino99 (9d9)]

@Valentin

when that report have been sent, your system was an dist-upgraded one. When you need to discover the real problem's source(s) its always better to start with a fresh installation (to get rid of old settings/profile that can hugely disturb the system).

As i can see you never did a fresh install after reporting that issue; and between "natty" time & now there is a very big gap, mainly about ipv4/ipv6 switches, kernel/drm updates, and all the now done processes to test/build the ubuntu packages.

That said, if you still have a such gap issue, follow the step above, and report a new bug with a system running a recent supported releases.

[Valentin Crone (va-crone)]

No it was a fresh install, and because of a bad amd driver I need to re-installl this 5 times, so be sure my report is about a fresh install, today I have always the problem, and I have not changed anything between the basic installation. (Just install the daily updates)

[The_Raven (originalraven)]

I have the same problem and i think in my case it's after standby.

[H.i.M (hir-i-mogul)]

Same problem here.
I wanted to migrate from Ubuntu 12.04.04 LTS to 16.04 and installed a new Ubuntu 16.04 LTS on a second SSD for testing on the same hardware. I was not moving my laptop in space during the testing. Both tests were performed on battery on 5GHZ wifi connected to a AVM Fritzbox 7490 router.

Complete system:
Dell Latitude E6400, RAM 4GB, CPU Intel E8400, Network controller: Intel Corporation Centrino Ultimate-N 6300 (rev 35)

Ubuntu 16.04 (with either original kernel 4.4 or last upstream kernel 4.6):
Linux X-Latitude-E6400 4.6.0-040600-generic #201605151930 SMP Sun May 15 23:32:59 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

X@X-Latitude-E6400:~$ iperf -c 192.168.10.11 -r -t 30
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
------------------------------------------------------------
Client connecting to 192.168.10.11, TCP port 5001
TCP window size: 136 KByte (default)
------------------------------------------------------------
[ 5] local 192.168.10.21 port 39466 connected with 192.168.10.11 port 5001
[ ID] Interval Transfer Bandwidth
[ 5] 0.0-30.1 sec 125 MBytes 34.8 Mbits/sec
[ 4] local 192.168.10.21 port 5001 connected with 192.168.10.11 port 60995
[ 4] 0.0-30.2 sec 206 MBytes 57.1 Mbits/sec

Ubuntu 12.04.04
Linux X-mobile 3.2.0-31-generic #50-Ubuntu SMP Fri Sep 7 16:16:45 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

X@X-mobile:~$ iperf -c 192.168.10.11 -t 30 -r
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
------------------------------------------------------------
Client connecting to 192.168.10.11, TCP port 5001
TCP window size: 23.5 KByte (default)
------------------------------------------------------------
[ 5] local 192.168.10.21 port 59437 connected with 192.168.10.11 port 5001
[ ID] Interval Transfer Bandwidth
[ 5] 0.0-30.0 sec 604 MBytes 169 Mbits/sec
[ 4] local 192.168.10.21 port 5001 connected with 192.168.10.11 port 32793
[ 4] 0.0-30.2 sec 668 MBytes 185 Mbits/sec

[The_Raven (originalraven)]

Ok, it has nothing to do with the "standby-mode".
But i found a solution that seems to work for me:
https://wiki.debian.org/iwlwifi
I edited "/etc/modprobe.d/iwlwifi.conf" and put this in it "options iwlwifi bt_coex_active=0 swcrypto=1 11n_disable=8" and it seems to work.
Give it a try. ;-)

[Valentin Crone (va-crone)]

I have always the same problem, on Ubuntu 14.04 LTS with Linux 4.2....

[H.i.M (hir-i-mogul)]

[edit]: I had to hide my previous comment as it contained private information.

Small improvement. Now 80Mbit/s instead of 50Mbit/s. But still not 185Mbit/s.

Adding this solution did not help too much in my case. I haven't reached the throughput i was used to before. In this test running Ubuntu 16.04 with all updates and standard kernel:

iperf -c 192.168.10.11 -r -t 30
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
------------------------------------------------------------
Client connecting to 192.168.10.11, TCP port 5001
TCP window size: 153 KByte (default)
------------------------------------------------------------
[ 5] local 192.168.10.21 port 33912 connected with 192.168.10.11 port 5001
[ ID] Interval Transfer Bandwidth
[ 5] 0.0-30.0 sec 289 MBytes 80.8 Mbits/sec
[ 4] local 192.168.10.21 port 5001 connected with 192.168.10.11 port 48268
[ 4] 0.0-30.5 sec 291 MBytes 79.9 Mbits/sec

[Hans Deragon (deragon)]

From http://www.intel.com/content/www/us/en/support/network-and-i-o/wireless-networking/000005511.html, one can conclude that this issue will probably never be fixed. The Ultimate-N 6300 is only supported for kernel 2.6.30. Obviously, it would be great for someone at Intel to confirm this. The driver persists in newer kernels, but if anybody is going to work on it to fix any problem remains to be seen.

[Rodney Beede (business2008+launchpad)]

I just tested and have the same issue. I tried the modprobe options idea with no change.

Ubuntu 16.10 64-bit.

4.8.0-41-generic #44-Ubuntu SMP

My next approach will be to try the firmware blob from Intel's website to see if pushing a newer one in helps.

[Rodney Beede (business2008+launchpad)]

dmesg | grep firmware

337586.320046] iwlwifi 0000:03:00.0: loaded firmware version 9.221.4.1 build 25532 op_mode iwldvm

[Rodney Beede (business2008+launchpad)]

Went to

http://www.intel.com/content/www/us/en/support/network-and-i-o/wireless-networking/000005511.html

and tried version 9.176 with no luck, same slow speeds.

loaded firmware version 9.176.4.1 build 15835 op_mode iwldvm

sudo mv -i ~rbeede/Downloads/iwlwifi-6000-4.ucode /lib/firmware
sudo modprobe -r iwlwifi; sudo modprobe iwlwifi; dmesg | grep firmware
sudo service network-manager restart

Will try the git repo latest build next. By chance is there a way to load the Windows firmware/drivers instead?

[Rodney Beede (business2008+launchpad)]

https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/log/iwlwifi-6000-4.ucode

Last activity in master branch was 2011-06-03 so not much hope.

[Rodney Beede (business2008+launchpad)]

Firmware changes did not help, but the following doubled my speed from 20mbps to 40mbps (still 50% lower than what I got in Windows 7):

vi /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf
Change line to

wifi.powersave = 2

echo "options iwlwifi 11n_disable=8" | sudo tee /etc/modprobe.d/iwlwifi11n.conf

[Valentin Crone (va-crone)]

Hello,
The file /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf doesn't exists on Ubuntu 14.04 LTS.
But I tried "options iwlwifi 11n_disable=8", I don't understand why "8" (because with "1" it doesn't change anything) but on my laptop:

The Wireless card connect faster to the AP and without errors.

In Download I have 8 - 8.3 MB/s (50% of the speed of Windows 7, but faster than before)
In Upload I have 15 - 15.5MB/s (Same speed as Windows 7, 7x - 15x faster than before)

My Laptop use Linux 3.13 (because of AMD Bullshit drivers) on Ubuntu 14.04 LTS.

Thanks you very much for your help ! (2 years later, but very appreciable :) )