How to decrease mouse speed (easy question, can't find answer)

Question

Hello Archers. I bought a new mouse which has a resolution of 800 DPI and no option to change it like game mice have (a button that changes colors when you change resolution with it). After connecting it to my Arch box it turned out to be faster then what I got used to with my previous mice that had an option to choose DPI. I would like to decrease speed of my pointer in IceWM Xorg. I don't have DE, just Xorg and IceWM.
xset m 0 0
won't do it, it just sets acceleration to 0. And apparently doesn't even work on newest systems.
Tried to add
Option "Resolution" "600"
to "xorg.conf" to try to change mouse resolution to 600 DPI and it had no effect.
There is also popular answer for this search query but it doesn't seem to answer my case. If I type in
xinput list
I have
⎜ ↳ USB OPTICAL MOUSE id=8 [slave pointer (2)]
as my mouse. Now
xinput list-props 8
and I get
Device ' USB OPTICAL MOUSE':
Device Enabled (141): 1
Coordinate Transformation Matrix (143): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
Device Product ID (259): 0, 1336
Device Node (260): "/dev/input/event2"
Evdev Axis Inversion (268): 0, 0
Evdev Axes Swap (270): 0
Axis Labels (271): "Rel X" (151), "Rel Y" (152), "Rel Vert Wheel" (263)
Button Labels (272): "Button Left" (144), "Button Middle" (145), "Button Right" (146), "Button Wheel Up" (147), "Button Wheel Down" (148), "Button Horiz Wheel Left" (149), "Button Horiz Wheel Right" (150)
Evdev Scrolling Distance (273): 1, 1, 1
Evdev Middle Button Emulation (274): 0
Evdev Middle Button Timeout (275): 50
Evdev Third Button Emulation (276): 0
Evdev Third Button Emulation Timeout (277): 1000
Evdev Third Button Emulation Button (278): 3
Evdev Third Button Emulation Threshold (279): 20
Evdev Wheel Emulation (280): 0
Evdev Wheel Emulation Axes (281): 0, 0, 4, 5
Evdev Wheel Emulation Inertia (282): 10
Evdev Wheel Emulation Timeout (283): 200
Evdev Wheel Emulation Button (284): 4
Evdev Drag Lock Buttons (285): 0
Luke in that answer pointed out "Device Accel Constant Deceleration (267): 2.500000" which I don't seem to have. So are there any working ways to decrease pointer speed in Xorg for Arch?
An LQ.org forum member suggested to look at wiki page which I did and the left solution also didn't help. Creating file "/etc/X11/xorg.conf.d/50-mouse-deceleration.conf" with the config wiki suggests doesn't decrease mouse speed. Please help me to do it.

Answer 1

Ok, bad dice. Last throw from me: Did you install: https://www.archlinux.org/packages/?sor … nput-mouse ?
man mouse_drv wrote:Option "Sensitivity" "float"
              Mouse movements are multiplied by this float before  being  pro‐
              cessed.  Use  this  mechanism to slow down high resolution mice.
              Because values bigger than 1.0 will result in not all pixels  on
              the  screen being accessible, you should better use mouse accel‐
              eration (see man xset) for  speeding  up  low  resolution  mice.
              Default: 1.0