Still hopelessly broken. :( Throughput with the latest kernel was down to about 45Mb/s when I tested it a few days ago.
-- 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/1795116 Title: large performance regression (~20-40%) in wifi with 4.15.0-33 and later Status in linux package in Ubuntu: Confirmed Bug description: 16.04 install using the HWE stack. after several weeks of uptime on -32, an update to -34 showed a major drop in wifi throughput, dependent solely on the kernel chosen: $ uname -a && ./wifibench.sh Linux brix 4.15.0-32-generic #35~16.04.1-Ubuntu SMP Fri Aug 10 21:54:34 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux Tue 25-Sep-18 06:07 PlatformSDK-SVR2003R2.iso 429,840,384 100% 8.41MB/s 0:00:48 (xfr#1, to-chk=0/1) sent 429,945,420 bytes received 35 bytes 8,685,766.77 bytes/sec $ uname -a && ./wifibench.sh Linux brix 4.15.0-34-generic #37~16.04.1-Ubuntu SMP Tue Aug 28 10:44:06 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux Tue 25-Sep-18 06:14 PlatformSDK-SVR2003R2.iso 429,840,384 100% 4.83MB/s 0:01:24 (xfr#1, to-chk=0/1) sent 429,945,420 bytes received 35 bytes 5,028,601.81 bytes/sec (the script is a simple rsync from a NAS. nothing in the NAS, or the router, or the physical positions of the devices or etc etc has changed, let alone in those 7 minutes). there is no interference, no other devices connected, etc. prior to the transfer, the link quality is 62-64 and the signal similarly weaker because of power saving, but once packets are in flight it looks perfect: $ iwconfig wlan0 IEEE 802.11 ESSID:"****" Mode:Managed Frequency:2.452 GHz Access Point: **** Bit Rate=150 Mb/s Tx-Power=20 dBm Retry short limit:7 RTS thr=2347 B Fragment thr:off Power Management:on Link Quality=70/70 Signal level=10 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:15 Missed beacon:0 the client is a J1900-based (baytrail) machine with a RTL8723BE wifi module. average performance while on -32 was consistently 70-80 Mb/s, over a period of several weeks. with -33 and later, it's generally 50-65. (that machine has no access to launchpad. i'll try apport-cli over the weekend). To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1795116/+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
