This issue appears to be an upstream bug, since you tested the latest upstream kernel. Would it be possible for you to open an upstream bug report[0]? That will allow the upstream Developers to examine the issue, and may provide a quicker resolution to the bug.
Please follow the instructions on the wiki page[0]. The first step is to email the appropriate mailing list. If no response is received, then a bug may be opened on bugzilla.kernel.org. Once this bug is reported upstream, please add the tag: 'kernel-bug- reported-upstream'. [0] https://wiki.ubuntu.com/Bugs/Upstream/kernel ** Changed in: linux (Ubuntu) Status: Incomplete => Triaged -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1319630 Title: 85% performance hit in iwlwifi from 12.04 to 14.04 Status in “linux” package in Ubuntu: Triaged Bug description: Summary: Almost 10 times slower speeds using 14.04 compared with 12.04 (same machine). Using iperf, Precise: 172 Mbits/sec. Trusty: 27.4 Mbits/sec. Using rsync: Precise: 19.83MB/s. Trusty: 3.12MB/s. Details: Machine: Laptop Toshiba Satellite A665 Triple boot Ubuntu 12.04, 13.04 and 14.04 Network (same network for both): d-link router 5Ghz rage Wireless card: Centrino $ lspci -nnk | grep -iA2 network 07:00.0 Network controller [0280]: Intel Corporation Centrino Advanced-N + WiMAX 6250 [Kilmer Peak] [8086:0087] (rev 5f) Subsystem: Intel Corporation Centrino Advanced-N + WiMAX 6250 2x2 AGN [8086:1301] Kernel driver in use: iwlwifi 12.04 Precise ####################################################################### $ lsb_release -a Distributor ID: Ubuntu Description: Ubuntu 12.04.4 LTS Release: 12.04 Codename: precise $ uname -a Linux vanhalen 3.2.0-29-generic #46-Ubuntu SMP Fri Jul 27 17:03:23 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux $ iperf -c reinhardt ------------------------------------------------------------ Client connecting to reinhardt, TCP port 5001 TCP window size: 23.5 KByte (default) ------------------------------------------------------------ [ 3] local 192.168.1.105 port 43135 connected with 192.168.1.1 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.0 sec 206 MBytes 172 Mbits/sec $ rsync -vP LAS.s22e10.432p.mp4 reinhardt:./ user@reinhardt's password: LAS.s22e10.432p.mp4 235861112 100% 19.83MB/s 0:00:11 (xfer#1, to-check=0/1) sent 235889984 bytes received 31 bytes 14296364.55 bytes/sec total size is 235861112 speedup is 1.00 14.04 Trusty ####################################################################### $ lsb_release -a Distributor ID: Ubuntu Description: Ubuntu 14.04 LTS Release: 14.04 Codename: trusty $ uname -a Linux vanhalen 3.13.0-24-generic #47-Ubuntu SMP Fri May 2 23:30:00 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux $ iperf -c reinhardt ------------------------------------------------------------ Client connecting to reinhardt, TCP port 5001 TCP window size: 85.0 KByte (default) ------------------------------------------------------------ [ 3] local 192.168.1.105 port 49807 connected with 192.168.1.1 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.1 sec 32.9 MBytes 27.4 Mbits/sec $ rsync -e "ssh -p2312" -vP LAS.s22e10.432p.mp4 reinhardt:./ user@reinhardt's password: LAS.s22e10.432p.mp4 235,861,112 100% 3.12MB/s 0:01:12 (xfr#1, to-chk=0/1) sent 235,918,776 bytes received 34 bytes 2,930,668.45 bytes/sec total size is 235,861,112 speedup is 1.00 ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-extra-3.13.0-24-generic 3.13.0-24.47 ProcVersionSignature: Ubuntu 3.13.0-24.47-generic 3.13.9 Uname: Linux 3.13.0-24-generic x86_64 NonfreeKernelModules: nvidia ApportVersion: 2.14.1-0ubuntu3.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: pablo 1977 F.... pulseaudio /dev/snd/controlC0: pablo 1977 F.... pulseaudio CurrentDesktop: Unity Date: Wed May 14 22:38:47 2014 HibernationDevice: RESUME=UUID=fed461e0-ae63-4fb1-8d92-8140a1b06551 InstallationDate: Installed on 2014-05-13 (2 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) MachineType: TOSHIBA Satellite A665 ProcFB: 0 VESA VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-24-generic root=UUID=77c75c70-93b5-41fa-984c-4fa7f9473ffc ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.13.0-24-generic N/A linux-backports-modules-3.13.0-24-generic N/A linux-firmware 1.127.2 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 09/14/10 dmi.bios.vendor: TOSHIBA dmi.bios.version: 1.80 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: NWQAA dmi.board.vendor: TOSHIBA dmi.board.version: 1.00 dmi.chassis.asset.tag: * dmi.chassis.type: 9 dmi.chassis.vendor: TOSHIBA dmi.chassis.version: N/A dmi.modalias: dmi:bvnTOSHIBA:bvr1.80:bd09/14/10:svnTOSHIBA:pnSatelliteA665:pvrPSAW3U-0DE039:rvnTOSHIBA:rnNWQAA:rvr1.00:cvnTOSHIBA:ct9:cvrN/A: dmi.product.name: Satellite A665 dmi.product.version: PSAW3U-0DE039 dmi.sys.vendor: TOSHIBA To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1319630/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
