USB WiFi much slower on Kubuntu than on Windows 8.1 [rtl8812au]

[Simon83]

I've been playing around with Linux for the past 2 months now, and I'm about to make the switch from Windows. The KDE Desktop is so nice, it really improved my daily workflow. Windows is like from the stone age compared to KDE (and other Linux desktops as well! Windows is just horrible compared to all of them).

There are just a few things I'd love to get sorted out. One of those things is my USB WiFi, which is much slower than under Windows.

I have an Edimax AC600 high gain USB dongle (5 GHz frequency), which requires the rtl8812au drivers. I've downloaded, compiled and installed the drivers from here: (can't post links it seems, but it's on github, user: gnab, repo: rtl8812au)

I have an 100 Mbit/s internet connection (via cable) and I did many speed tests under Linux and Windows (testing always against the same server).
Under Linux I get max. ~50 Mbit/s download speed, while on Windows I get ~85 Mbit/s (with an ethernet cable I can get almost the full 100 Mbit/s, but unfortunately I have to use WiFi). And like I said, I tested this multiple times and the results are always about the same.

This is not a major deal breaker for me, 50 Mbit/s isn't slow at all, but since I'm paying for 100 Mbit it'd be still nice if I could get the max out of my internet connection.

I think the reason could be simply that the Windows drivers are simply better than the Linux ones. But since I'm a Linux noob I'm not really sure, so maybe I'm missing something and there are some tricks to get the same speed like I get on Windows. I'd appreciate any input regarding that matter!

I'm using the latest Kubuntu 15.04 Beta by the way. Here are some infos about my system, but I'm not really sure what might be relevant. Just let me know if you need additional information, I'd be more than happy to provide them.

lsusb:

Bus 004 Device 004: ID 7392:a812 Edimax Technology Co., Ltd

dmesg:

[  229.945481] RTL871X: rtl8812au driver version=v4.2.2_7502.20130517[  229.945521] RTL871X: 
[  229.945524] RTL871X: bLength=7
[  229.945525] RTL871X: bDescriptorType=5
[  229.945526] RTL871X: bEndpointAddress=84
[  229.945527] RTL871X: wMaxPacketSize=512
[  229.945528] RTL871X: bInterval=0
[  229.945529] RTL871X: RT_usb_endpoint_is_bulk_in = 4
[  229.945531] RTL871X: 
[  229.945532] RTL871X: bLength=7
[  229.945533] RTL871X: bDescriptorType=5
[  229.945534] RTL871X: bEndpointAddress=5
[  229.945536] RTL871X: wMaxPacketSize=512
[  229.945537] RTL871X: bInterval=0
[  229.945538] RTL871X: RT_usb_endpoint_is_bulk_out = 5
[  229.945539] RTL871X: 
[  229.945541] RTL871X: bLength=7
[  229.945542] RTL871X: bDescriptorType=5
[  229.945543] RTL871X: bEndpointAddress=6
[  229.945544] RTL871X: wMaxPacketSize=512
[  229.945545] RTL871X: bInterval=0
[  229.945546] RTL871X: RT_usb_endpoint_is_bulk_out = 6
[  229.945547] RTL871X: 
[  229.945548] RTL871X: bLength=7
[  229.945550] RTL871X: bDescriptorType=5
[  229.945551] RTL871X: bEndpointAddress=87
[  229.945552] RTL871X: wMaxPacketSize=64
[  229.945553] RTL871X: bInterval=3
[  229.945554] RTL871X: RT_usb_endpoint_is_int_in = 7, Interval = 3
[  229.945555] RTL871X: 
[  229.945557] RTL871X: bLength=7
[  229.945558] RTL871X: bDescriptorType=5
[  229.945559] RTL871X: bEndpointAddress=8
[  229.945560] RTL871X: wMaxPacketSize=512
[  229.945561] RTL871X: bInterval=0
[  229.945562] RTL871X: RT_usb_endpoint_is_bulk_out = 8
[  229.945563] RTL871X: 
[  229.945565] RTL871X: bLength=7
[  229.945566] RTL871X: bDescriptorType=5
[  229.945567] RTL871X: bEndpointAddress=9
[  229.945568] RTL871X: wMaxPacketSize=512
[  229.945569] RTL871X: bInterval=0
[  229.945570] RTL871X: RT_usb_endpoint_is_bulk_out = 9
[  229.945571] RTL871X: nr_endpoint=6, in_num=2, out_num=4
[  229.945573] RTL871X: USB_SPEED_HIGH
[  229.945581] RTL871X: CHIP TYPE: RTL8811AU or RTL8821U
[  229.945589] RTL871X: register rtw_netdev_ops to netdev_ops
[  229.949727] RTL871X: ReadChipVersion8812A SYS_CFG(0xF0)=0x04411535 
[  229.949946] RTL871X: Chip Version Info: CHIP_8821_Normal_Chip_TSMC_B_CUT_1T1R_RomVer(0)
[  229.949950] RTL871X: RF_Type is 3!!
[  229.949952] RTL871X: _ConfigChipOutEP_8812 OutEpQueueSel(0x07), OutEpNumber(4) 
[  229.949954] RTL871X: ====> ReadAdapterInfo8812AU
[  229.950059] RTL871X: Boot from EFUSE, Autoload OK !
[  230.114121] RTL871X: EEPROM ID=0x8129
[  230.114125] RTL871X: VID = 0x7392, PID = 0xA812
[  230.114127] RTL871X: Customer ID: 0x00, SubCustomer ID: 0xCD
[  230.114130] RTL871X: hal_ReadMACAddress_8812AU MAC Address from EFUSE = 74:da:38:10:28:d1
[  230.114136] RTL871X: ==>mpt_GetChnlGroup8812A in 5G, but Channel 163 in Group not found 
[  230.114139] RTL871X: ==>mpt_GetChnlGroup8812A in 5G, but Channel 163 in Group not found 
[  230.114142] RTL871X: ==>mpt_GetChnlGroup8812A in 5G, but Channel 163 in Group not found 
[  230.114145] RTL871X: ==>mpt_GetChnlGroup8812A in 5G, but Channel 163 in Group not found 
[  230.114147] RTL871X: EEPROMRegulatory = 0x0 TxPwrCalibrateRate=0x0
[  230.114148] RTL871X: Board Type: 0x 0
[  230.114150] RTL871X: mlmepriv.ChannelPlan = 0x7f
[  230.114151] RTL871X: CrystalCap: 0x15
[  230.114152] RTL871X: ThermalMeter = 0x20
[  230.114154] RTL871X: SWAS: bHwAntDiv = 1, TRxAntDivType = 3
[  230.114155] RTL871X: pHalData->PAType_2G is 0x0, pHalData->ExternalPA_2G = 0
[  230.114157] RTL871X: pHalData->PAType_5G is 0x0, pHalData->ExternalPA_5G = 0
[  230.114158] RTL871X: pHalData->LNAType_2G is 0x0, pHalData->ExternalLNA_2G = 0
[  230.114159] RTL871X: pHalData->LNAType_5G is 0x0, pHalData->ExternalLNA_5G = 0
[  230.114161] RTL871X: PID= 0xa812, VID=  7392
[  230.114162] RTL871X: PID= 0xa812, VID=  7392
[  230.114164] RTL871X: Customer ID: 0x 0
[  230.117116] RTL871X: ReadAdapterInfo8812AU <====
[  230.117151] RTL871X: init_channel_set ChannelPlan ID 7f Chan num:38  
[  230.117319] RTL871X: can't get autopm: 
[  230.117322] RTL871X: rtw_macaddr_cfg MAC Address  = 74:da:38:10:28:d1
[  230.117324] RTL871X: bDriverStopped:1, bSurpriseRemoved:0, bup:0, hw_init_completed:0
[  230.117881] RTL871X: _rtw_drv_register_netdev, MAC Address (if1) = 74:da:38:10:28:d1
[  230.140433] RTL871X: rtw_wx_set_scan: bDriverStopped=1, bup=0, hw_init_completed=0
[  230.141125] RTL871X: +871x_drv - drv_open, bup=0
[  230.142802] RTL871X:  power-on :REG_SYS_CLKR 0x09=0x30. REG_CR 0x100=0xea.
[  230.142805] RTL871X:  MAC has not been powered on yet.
[  230.214396] RTL871X:  ===> FirmwareDownload8812() fw source from Header.
[  230.214410] RTL871X:  ===> FirmwareDownload8812() fw:Firmware for NIC, size: 31972
[  230.214412] RTL871X: FirmwareDownload8812: fw_ver=11 fw_subver=0 sig=0x2101
[  230.262225] RTL871X: _FWFreeToGo8812: Checksum report OK! REG_MCUFWDL:0x00070304
[  230.263347] RTL871X: =====> _8051Reset8812(): 8051 reset success .
[  230.292446] RTL871X: _FWFreeToGo8812: Polling FW ready success!! REG_MCUFWDL:0x000706c6
[  230.292449] RTL871X: rtl8812au_hal_init: Download Firmware Success!!
[  230.316169] RTL871X: ===> phy_BB8812_Config_ParaFile() EEPROMRegulatory 0
[  230.515727] RTL871X: ==>  _InitAntenna_Selection_8812A ....
[  230.516227] RTL871X: _InitAntenna_Selection_8812A,Cur_ant:(2)AUX_ANT
[  230.517230] RTL871X: pDM_Odm TxPowerTrackControl = 1
[  230.518971] RTL871X: MAC Address from REG_MACID = 74:da:38:10:28:d1
[  230.518973] RTL871X: rtl8812au_hal_init in 380ms
[  230.518976] RTL871X: MAC Address = 74:da:38:10:28:d1
[  230.519389] RTL871X: 3Unable to create rtw_proc directory
[  230.519393] RTL871X: -871x_drv - drv_open, bup=1
[  230.519828] RTL871X: (2)871x_drv - drv_close, bup=1, hw_init_completed=1
[  230.521511] RTL871X: indicate disassoc
[  230.521533] RTL871X: rtl8812_set_FwJoinBssReport_cmd mstatus(0)
[  230.522472] RTL871X: -871x_drv - drv_close, bup=1
[  230.522803] RTL871X: set_mode = IW_MODE_INFRA
[  230.522846] RTL871X: +871x_drv - drv_open, bup=1
[  230.522861] RTL871X: -871x_drv - drv_open, bup=1
[  230.523345] RTL871X: hw_var_set_opmode()-4268 mode = 2
[  230.589268] RTL871X: [rtw_wx_set_pmkid] IW_PMKSA_FLUSH!
[  230.589277] RTL871X: set_mode = IW_MODE_INFRA
[  230.589300] RTL871X: set bssid:00:00:00:00:00:00
[  230.589366] RTL871X: =>rtw_wx_set_essid
[  230.589368] RTL871X: ssid=g\xffffffc6isQ\xffffffffJ\xffffffec)ͺ\xffffffab\xfffffff2\xfffffffb\xffffffe3F|\xffffffc2T\xfffffff8\xffffffe8\xffffffe7\xffffff8dvZ.c3\xffffff9fɚ0\xffffffcc\xffffff88\xffffffff\xffffffff, len=32
[  230.589380] RTL871X: set ssid [g\xffffffc6isQ\xffffffffJ\xffffffec)ͺ\xffffffab\xfffffff2\xfffffffb\xffffffe3F|\xffffffc2T\xfffffff8\xffffffe8\xffffffe7\xffffff8dvZ.c3\xffffff9fɚ_\xffffff88\xffffffd9] fw_state=0x00000008
[  230.589381] RTL871X: Set SSID under fw_state=0x00000008
[  230.589386] RTL871X: <=rtw_wx_set_essid, ret 0
[  230.589809] RTL871X: hw_var_set_opmode()-4268 mode = 2
[  230.601280] RTL871X: [rtw_wx_set_pmkid] IW_PMKSA_FLUSH!
[  234.696518] RTL871X: survey done event(5a)
[  234.696527] RTL871X: rtw_select_and_join_from_scanned_queue: return _FAIL(candidate == NULL)
[  234.696529] RTL871X: try_to_join, but select scanning queue fail, to_roaming:0
[  236.535326] RTL871X: ==>rtw_ps_processor .fw_state(8)
[  236.535331] RTL871X: ==>ips_enter cnts:1
[  236.535332] RTL871X: nolinked power save enter
[  236.535334] RTL871X: ===> rtw_ips_pwr_down...................
[  236.535335] RTL871X: ====> rtw_ips_dev_unload...
[  236.558768] RTL871X: usb_read_port_cancel
[  236.558947] RTL871X: usb_read_port_complete() RX Warning! bDriverStopped(0) OR bSurpriseRemoved(0) bReadPortCancel(1)
[  236.559193] RTL871X: usb_read_port_complete() RX Warning! bDriverStopped(0) OR bSurpriseRemoved(0) bReadPortCancel(1)
[  236.559445] RTL871X: usb_read_port_complete() RX Warning! bDriverStopped(0) OR bSurpriseRemoved(0) bReadPortCancel(1)
[  236.559695] RTL871X: usb_read_port_complete() RX Warning! bDriverStopped(0) OR bSurpriseRemoved(0) bReadPortCancel(1)
[  236.559752] RTL871X: usb_write_port_cancel 
[  236.559779] RTL871X: ==> rtl8812au_hal_deinit 
[  236.563938] RTL871X: =====> _8051Reset8812(): 8051 reset success .
[  236.566933] RTL871X: <=== rtw_ips_pwr_down..................... in 28ms
[  238.477708] RTL871X: wpa_set_auth_algs, AUTH_ALG_OPEN_SYSTEM
[  238.477713] RTL871X: _rtw_pwr_wakeup call ips_leave....
[  238.477714] RTL871X: ==>ips_leave cnts:1
[  238.477715] RTL871X: ===>  rtw_ips_pwr_up..............
[  238.477717] RTL871X: ===> ips_netdrv_open.........
[  238.477973] RTL871X:  power-on :REG_SYS_CLKR 0x09=0x30. REG_CR 0x100=0xea.
[  238.477976] RTL871X:  MAC has not been powered on yet.
[  238.549125] RTL871X:  ===> FirmwareDownload8812() fw source from Header.
[  238.549130] RTL871X:  ===> FirmwareDownload8812() fw:Firmware for NIC, size: 31972
[  238.549133] RTL871X: FirmwareDownload8812: fw_ver=11 fw_subver=0 sig=0x2101
[  238.594080] RTL871X: _FWFreeToGo8812: Checksum report OK! REG_MCUFWDL:0x00070604
[  238.595203] RTL871X: =====> _8051Reset8812(): 8051 reset success .
[  238.624300] RTL871X: _FWFreeToGo8812: Polling FW ready success!! REG_MCUFWDL:0x000706c6
[  238.624316] RTL871X: rtl8812au_hal_init: Download Firmware Success!!
[  238.648027] RTL871X: ===> phy_BB8812_Config_ParaFile() EEPROMRegulatory 0
[  238.847728] RTL871X: ==>  _InitAntenna_Selection_8812A ....
[  238.848205] RTL871X: _InitAntenna_Selection_8812A,Cur_ant:(2)AUX_ANT
[  238.849209] RTL871X: pDM_Odm TxPowerTrackControl = 1
[  238.850956] RTL871X: MAC Address from REG_MACID = 74:da:38:10:28:d1
[  238.850968] RTL871X: rtl8812au_hal_init in 372ms
[  238.850977] RTL871X: <===  rtw_ips_pwr_up.............. in 372ms
[  238.850979] RTL871X: nolinked power save leave
[  238.851080] RTL871X: ==> ips_leave.....LED(0x01828282)...
[  238.851082] RTL871X: set_mode = IW_MODE_INFRA
[  238.851108] RTL871X: 
[  238.851111] RTL871X: 0x30 0x14 0x01 0x00 0x00 0x0f 0xac 0x02 
[  238.851113] RTL871X: 0x01 0x00 0x00 0x0f 0xac 0x04 0x01 0x00 
[  238.851115] RTL871X: 0x00 0x0f 0xac 0x02 0x00 0x00 0x00 0x00 
[  238.851581] RTL871X: hw_var_set_opmode()-4268 mode = 2
[  238.851955] RTL871X: SetHwReg8812A, 5005, RCR= 740060ca
[  238.851969] RTL871X: =>rtw_wx_set_essid
[  238.851971] RTL871X: ssid=home-wlan, len=14
[  238.851975] RTL871X: set ssid [home-wlan] fw_state=0x00000008
[  238.851976] RTL871X: Set SSID under fw_state=0x00000008
[  238.851980] RTL871X: [by_bssid:0][assoc_ssid:home-wlan][to_roaming:0] new candidate: home-wlan(00:26:5a:c7:6a:f5) rssi:-59
[  238.851983] RTL871X: rtw_select_and_join_from_scanned_queue: candidate: home-wlan(00:26:5a:c7:6a:f5, ch:48)
[  238.851988] RTL871X: [VHT] Support STBC = 0x01
[  238.851991] RTL871X: link to Artheros AP
[  238.851993] RTL871X: <=rtw_wx_set_essid, ret 0
[  238.851999] RTL871X: set bssid:00:26:5a:c7:6a:f5
[  238.852001] RTL871X: Set BSSID under fw_state=0x00000088
[  238.852956] RTL871X: set HT ch/bw before connected
[  239.142502] RTL871X: link to Artheros AP
[  239.142518] RTL871X: issue_deauth to 00:26:5a:c7:6a:f5
[  239.142527] RTL871X: start auth
[  239.142531] RTL871X: issue_auth
[  239.144469] RTL871X: OnAuthClient
[  239.144480] RTL871X: auth success, start assoc
[  239.144488] RTL871X: network.SupportedRates[0]=8C
[  239.144491] RTL871X: network.SupportedRates[1]=12
[  239.144494] RTL871X: network.SupportedRates[2]=98
[  239.144496] RTL871X: network.SupportedRates[3]=24
[  239.144498] RTL871X: network.SupportedRates[4]=B0
[  239.144500] RTL871X: network.SupportedRates[5]=48
[  239.144503] RTL871X: network.SupportedRates[6]=60
[  239.144505] RTL871X: network.SupportedRates[7]=6C
[  239.144507] RTL871X: bssrate_len = 8
[  239.146465] RTL871X: OnAssocRsp
[  239.146481] RTL871X: report_join_res(2)
[  239.146486] RTL871X: rtw_joinbss_update_network
[  239.146490] RTL871X: +rtw_update_ht_cap()
[  239.146496] RTL871X: rtw_alloc_macid = 0
[  239.146499] RTL871X: rtw_joinbss_update_stainfo
[  239.146502] RTL871X: ### Set STA_(0) info
[  239.146520] RTL871X: BSSID:00:26:5a:c7:6a:f5
[  239.146527] RTL871X: assoc success
[  239.146550] RTL871X: OnAction_back
[  239.146553] RTL871X: OnAction_back, action=0
[  239.146558] RTL871X: issue_action_BA, category=3, action=1, status=0
[  239.147415] RTL871X: WMM(0): 0, a42b
[  239.147538] RTL871X: WMM(1): 0, a44f
[  239.147708] RTL871X: WMM(2): 0, 5e4322
[  239.147788] RTL871X: WMM(3): 0, 2f3222
[  239.147790] RTL871X: wmm_para_seq(0): 0
[  239.147791] RTL871X: wmm_para_seq(1): 1
[  239.147793] RTL871X: wmm_para_seq(2): 2
[  239.147794] RTL871X: wmm_para_seq(3): 3
[  239.147795] RTL871X: HTOnAssocRsp
[  239.148014] RTL871X: VHTOnAssocRsp
[  239.148027] RTL871X: rtl8812_set_raid_cmd, bitmap=0xff010, mac_id=0x0, raid=0x5, shortGIrate=1
[  239.148855] RTL871X: send eapol packet
[  239.149184] RTL871X: [MacId],  Set MacId Ctrl(original) = 0x10000 
[  239.151424] RTL871X: send eapol packet
[  239.151449] RTL871X:  ~~~~set sta key:unicastkey
[  239.151512] RTL871X:  ~~~~set sta key:groupkey
[  239.151515] RTL871X: ==> rtw_set_key algorithm(2),keyid(2),key_mask(0)
[  239.152065] RTL871X: rtl8812_set_FwJoinBssReport_cmd mstatus(1)
[  239.153412] RTL871X: SetFwRsvdPagePkt_8812: Set RSVD page location to Fw ,TotalPacketLen(1024), TotalPageNum(4)
[  239.154405] RTL871X: rtl8812_set_FwJoinBssReport_cmd: 1 Download RSVD success! DLBcnCount:1, poll:1
[  239.155154] RTL871X: Set RSVD page location to Fw.
[  239.155315] RTL871X: =>mlmeext_joinbss_event_callback
[  239.156805] RTL871X: set pairwise key to hw: alg:4(WEP40-1 WEP104-5 TKIP-2 AES-4) camid:4
[  239.156810] RTL871X: set group key to hw: alg:2(WEP40-1 WEP104-5 TKIP-2 AES-4) keyid:2
[  239.158653] RTL871X: SetHwReg8812A, 4998, RCR= 740060ce
[  243.851954] RTL871X: rtl8812_set_raid_cmd, bitmap=0xff000, mac_id=0x0, raid=0x5, shortGIrate=1
[  253.858912] RTL871X: rtw_set_ps_mode: Enter 802.11 power save
[  253.860662] RTL871X: rtl8812_set_FwPwrMode_cmd: Mode=1 SmartPS=2 UAPSD=0
[  279.449159] RTL871X: rtw_set_ps_mode: Leave 802.11 power save
[  279.449166] RTL871X: rtl8812_set_FwPwrMode_cmd: Mode=0 SmartPS=2 UAPSD=0
[  281.888613] RTL871X: rtw_set_ps_mode: Enter 802.11 power save
[  281.888620] RTL871X: rtl8812_set_FwPwrMode_cmd: Mode=1 SmartPS=2 UAPSD=0
[  309.917261] RTL871X: rtw_set_ps_mode: Leave 802.11 power save
[  309.917267] RTL871X: rtl8812_set_FwPwrMode_cmd: Mode=0 SmartPS=2 UAPSD=0
[  311.484052] RTL871X: rtw_issue_addbareq_cmd, p=0
[  311.484099] RTL871X: issue_action_BA, category=3, action=0, status=0
[  311.484103] RTL871X: BA_starting_seqctrl = 300 for TID=0
[  311.486087] RTL871X: OnAction_back
[  311.486089] RTL871X: OnAction_back, action=1
[  311.486091] RTL871X: agg_enable for TID=0

[SecretCode]

Is it just speed? You don't get connection errors or drop-outs?

This may not help, but it's something that has made a massive difference to me in the past.

Go to the properties of the wifi connection (in 14.04, click the spanner next to the connection from the Network Management icon in the system tray ... may be different in 15.04). Change the "MTU" value to 1400 (it may be Automatic by default). See if this makes a difference.

If it does, then 1492 or 1472 are probably the optimal values. The Path MTU (pmtu) value revealed by the command

tracepath www.kubuntuforums.net

will almost certainly be 1500, but depending on your driver and router and ISP setup, the connection may need a lower value set deducting 8 bytes or 8+20 bytes of overhead.

[SecretCode]

If that doesn't help, it's probably the driver. Microsoft bullies hardware vendors to test and optimise their products for the windows hardware compatibility logo. The Linux world doesn't have bullying. At least, not such commercial bullying.

[Simon83]

Hey SecretCode, thanks alot!

Yes, it is just speed, no connection errors or drop-outs so far.

Do I need to reboot or something after changing the MTU? Because it didn't seem to make a difference, but the tracepath is still showing PMTU at 1500. I suppose it should show up as 1400, after changing the MTU to 1400, correct?

Anyway, I'm finishing some work and then I'll reboot anyway and check again if it made a difference.

[SecretCode]

No, the tests will show the same value (or fail completely!) regardless of the settings. I think.

[Simon83]

I've just rebooted and tracepath does now report a PMTU of 1400, so it seems a reboot is required (or maybe an ifconfig down/up would have worked too, haven't checked unfortunately, it just hit me now).
Unfortunately no speed gain with a TMU of 1400

Ah well, it will be the Linux drivers I guess, and as you pointed out, Microsoft is very strict with regards to driver certifications, so it's very likely that the Windows drivers are of higher quality.

I'm considering to buy another USB WiFi dongle. The Edimax AC600 I recently bought was quite cheap, it did cost around 25€, so not a big loss. I'm now doing some Google searches for the "best" WiFi chipsets for Linux, but every search related to "WiFi" and "Linux" just comes up with so much unrelated stuff.

Can you (or someone else) recommend me a reliable WiFi chipsets, that can be found on USB adapters and support 5Ghz with a/c? If not I'll just keep searching, and eventually I'll find something

Thanks alot for your help so far!