The headline specifications
The PixArt PAW3395 is a flagship optical gaming sensor rated for 26,000 DPI, 650 IPS tracking speed, 50 G acceleration tolerance and a selectable lift-off distance down to 1 mm. It is designed for low-power wireless operation, which is why it appears in most modern sub-60 g wireless mice.
In plain terms: 650 IPS is roughly 16.5 m/s of hand movement. No human flick comes close, so tracking speed stops being a limitation and the sensor's behaviour under normal motion becomes the thing that matters.
Why 'no smoothing, no acceleration' matters
Cheaper sensors smooth their output at high speed to hide noise, which delays and rounds off fast movements. Angle snapping straightens near-horizontal motion so lines look clean but your aim is being edited.
The PAW3395 needs none of it in its default configuration, so a micro-correction of half a millimetre reaches the game as a micro-correction, not as a filtered approximation.
Lift-off distance and motion sync
A 1 mm lift-off distance means tracking stops almost as soon as the mouse leaves the pad. Low-sensitivity players reposition dozens of times per round, and a high LOD adds unwanted movement on every one of them.
Motion sync aligns the sensor's sampling with the USB report window, so each report contains a freshly captured position instead of one aged by a fraction of a cycle. It slightly increases average latency but makes it far more consistent, which most players prefer.
PAW3395 in context
Against older sensors such as the PAW3370, the 3395 improves tracking speed, acceleration tolerance and power efficiency — the last of which is what makes long battery life at high polling rates possible.
Against newer flagship parts, the practical differences are in power draw and maximum ratings rather than in anything you can feel while aiming. Shape, weight and firmware tuning separate good mice far more than the sensor die does today.