Jtdcftul

Over a couple hours on this problem, I plugged the mouse into the USB3 port and it's just fine. Mouse has terrible lag on the USB2 ports.

I changed a few things that made no difference I could tell, though the settings persist, and may have solved the problem on the USB3 ports.

This seems nasty and it might help to know why switching from normal to low latency kernel might cause the mouse, and keyboard, to lag. (I changed to a PS2 keyboard to solve for keyboard.)

Before the confusion, i set nvidia's "cool-bits" and "allow-empty-initial-configuration", which zonked one of the monitors. Then the input lag started, but after rebooting, worked. So I'm sorry if this is an nvidia settings problem, tho it seems liable to happen again.

some commands I ran, settings I've changed

 ~ inxi -SCG

System:    Host: home Kernel: 4.18.0-14-lowlatency x86_64 bits: 64 Desktop: Gnome 3.30.2 

           Distro: Ubuntu 18.10 (Cosmic Cuttlefish) 

CPU:       Topology: 8-Core model: AMD FX-8320 bits: 64 type: MCP L2 cache: 2048 KiB 

           Speed: 1432 MHz min/max: 1400/4000 MHz Core speeds (MHz): 1: 1429 2: 1429 3: 1433 4: 1427 5: 1434 

           6: 1434 7: 1521 8: 1446 

Graphics:  Device-1: NVIDIA GM107 [GeForce GTX 750 Ti] driver: nvidia v: 390.87 

           Display: x11 server: X.Org 1.20.3 driver: nvidia resolution: 1680x1050~61Hz 

           OpenGL: renderer: GeForce GTX 750 Ti/PCIe/SSE2 v: 4.6.0 NVIDIA 390.87



 ~ sudo lsmod | grep -i usbhid

usbhid                 49152  0

hid                   126976  2 usbhid,hid_generic

 ~ cat /sys/module/usbhid/parameters/mousepoll 

4

xorg.conf

 ~ cat /etc/X11/xorg.conf

# nvidia-xconfig: X configuration file generated by nvidia-xconfig

# nvidia-xconfig:  version 390.87  (buildmeister@swio-display-x64-rhel04-14)  Tue Aug 21 17:33:38 PDT 2018



# nvidia-settings: X configuration file generated by nvidia-settings

# nvidia-settings:  version 390.77  (buildd@lgw01-amd64-035)  Thu Aug  2 14:55:24 UTC 2018



Section "ServerLayout"

    Identifier     "Layout0"

    Screen      0  "Screen0" 0 0

    InputDevice    "Keyboard0" "CoreKeyboard"

    InputDevice    "Mouse0" "CorePointer"

    Option         "Xinerama" "0"

EndSection



Section "Files"

EndSection



Section "InputDevice"



    # generated from default

    Identifier     "Mouse0"

    Driver         "mouse"

    Option         "Protocol" "auto"

    Option         "Device" "/dev/psaux"

    Option         "Emulate3Buttons" "no"

    Option         "ZAxisMapping" "4 5"

    Option         "AccelerationNumerator" "8"

    Option         "AccelerationDenominator" "1"

EndSection



Section "InputDevice"



    # generated from default

    Identifier     "Keyboard0"

    Driver         "kbd"

EndSection



Section "Monitor"

    Identifier     "Monitor0"

    VendorName     "Unknown"

    ModelName      "Samsung SyncMaster"

    HorizSync       30.0 - 81.0

    VertRefresh     56.0 - 75.0

    Option         "DPMS"

EndSection



Section "Device"

    Identifier     "Device0"

    Driver         "nvidia"

    VendorName     "NVIDIA Corporation"

    BoardName      "GeForce GTX 750 Ti"

EndSection



Section "Screen"

    Identifier     "Screen0"

    Device         "Device0"

    Monitor        "Monitor0"

    DefaultDepth    24

    Option         "AllowEmptyInitialConfiguration" "True"

    Option         "Coolbits" "31"

    Option         "Stereo" "0"

    Option         "nvidiaXineramaInfoOrder" "DFP-0"

    Option         "metamodes" "DVI-I-1: 1680x1050_60 +0+0, HDMI-0: 1680x1050_60 +1680+0"

    Option         "SLI" "Off"

    Option         "MultiGPU" "Off"

    Option         "BaseMosaic" "off"

    SubSection     "Display"

        Depth       24

    EndSubSection

EndSection