Mouse & Hardware Terminology Glossary
Clear, engineering-grade definitions of essential gaming peripheral specifications, optical sensor dynamics, switch mechanical chatter, and sensitivity mathematics.
Polling Rate (Hz)
The frequency (in Hertz/seconds) at which a USB gaming mouse reports its cursor position and button input states to the computer operating system. Standard mice report at 125Hz (8ms latency), gaming mice at 1000Hz (1ms latency), and ultra-high polling mice at 2000Hz–8000Hz (0.5ms–0.125ms latency).
CPI & DPI
CPI (Counts Per Inch) and DPI (Dots Per Inch) measure optical mouse sensor hardware sensitivity — specifically how many counts or steps the sensor registers per physical inch of movement across the mousepad surface.
eDPI (Effective DPI)
Effective Dots Per Inch (eDPI) is calculated by multiplying physical Mouse DPI by In-Game Sensitivity setting (eDPI = Mouse DPI × In-Game Sens). It provides a standardized metric for comparing mouse sensitivity across players using different DPI hardware presets.
Switch Debounce Delay
Debounce delay is a firmware timer or algorithm designed to ignore secondary mechanical electrical chatter (bounce) created when physical metal contacts snap together inside a mechanical switch.
Optical vs Mechanical Switch
Mechanical switches rely on physical metallic leaf contacts, making them vulnerable to oxidation and bounce over time. Optical switches use an infrared light beam interrupted by a plastic stem, offering zero debounce delay and immunity to double-click wear.
CPS (Clicks Per Second)
Clicks Per Second (CPS) measures how many times a user can actuate the primary mouse button in a 1-second window. Testing techniques include Regular Single Clicking, Jitter Clicking, Butterfly Clicking, and Drag Clicking.
NKRO & Key Rollover
N-Key Rollover (NKRO) indicates that a mechanical keyboard hardware controller can register every key pressed simultaneously without key ghosting or missed inputs.
Rapid Trigger (Hall Effect)
Rapid Trigger dynamically resets key actuation the exact millisecond a key switch moves upward, without needing to pass a static fixed reset point.
Yaw Angle
Yaw is the game engine multiplier angle constant used to convert mouse count inputs into 360-degree horizontal camera rotation angles in 3D FPS game engines.