I have the exact same problem. Floaty mouse, a little bit of input lag -- almost unnoticeable mainly because I run very powerful computer but its there. When I'm in any game when I pan camera slowly I can see the stutter. Same in windows when I drag mouse very slowly across I can see the micro-stutter, something feels bottlenecked, even in bios mouse is 'floaty'
Tried pretty much everything.
- Completely new hardware throughout
- Driver overhaul
- Delete mouse drivers and all mouse files + resinstall
- Windows 10 tweaks + Xbox removal + Cortana removal
- Installed old windows 7
- Tried installed raw mouse program
- Many bios tweaks (hpet etc)
Nothing has helped, really at a loss. Been this way now for best part of 2 years.
Any help would be greatly appreciated