LogitechMx518 Legendary

All mice contain a small circuit board inside to handle the connection between inputs and the computer. Some are more complex than others, which is why these so-called Microcontroller Units (MCUs) are needed, which are essentially specialized miniature computers. Most modern mice today are equipped with more complex microcontrollers to manage things like stored profiles and CPI settings and to ensure a smooth connection, especially in wireless mice.

The resolution of a mouse, also known as CPI, indicates how many pixels the cursor on the screen moves when you move the mouse one inch on the mousepad or table. Many mouse manufacturers and some online sources use the term DPI to refer to the same thing. However, DPI stands for ‘Dots per Inch’ and refers more to screen resolutions, while CPI stands for ‘Counts per Inch’ and directly relates to the sensitivity of a mouse. The higher the CPI of a mouse, the “finer/more precise/more frequent” the sensor can scan the surface. However, this does not mean you should play with the highest CPI.

The polling rate, also known as the report rate, is the frequency at which the mouse communicates with the computer and makes inputs (responds). The polling rate is measured in Hz and can vary between 125 Hz and 8,000 Hz depending on the brand and model of the mouse in question. For example, a mouse with a polling rate set to 1,000 Hz will update its position on the screen 1,000 times per second, or every 1 ms. The higher the polling rate, the more “real-time” the cursor movement you see on the screen will be.

The Lift-Off Distance (LOD) refers to the height at which a mouse sensor stops tracking the surface it’s on. A high LOD means that the mouse continues to track even when lifted off the surface. Therefore, a low LOD allows tracking to stop sooner, preventing unwanted mouse behavior. On the other hand a higher LOD means the mouse will draw more energy which often results in a crispier feeling but for the cost of less battery life.

Many of the latest high-end gaming mice offer the option to enable Motion Sync, which synchronizes SPI reads with USB polling, resulting in less jitter. This feature is often found in PixArt 3370 or newer sensors. Motion Sync has its pros and cons, and whether or not to use it often depends on the games you play and how much you notice these extremely fine differences.

When correctly implemented, Motion Sync promises higher sensor reactivity by synchronizing the signals the mouse sends at the exact intervals the PC is looking for these data. This leads to more consistent data exchange, which helps in tracking targets better. However, while Motion Sync is enabled and the sensor tracks more consistently, it pushes data to the next polling event, leading to a minimal higher input delay of a few milliseconds, depending on the MCU and sensor used, which polling rate is utilized, and how much power the components are allowed to draw (LP, HP, Corded / God Mode). In short, Motion Sync is comparable to VRR technologies like G-Sync, where one must decide if they are willing to sacrifice a minimal delay for a smoother experience on the monitor.

I currently recommend disabling Motion Sync

Debounce is the time a switch takes to register a keypress or mouse click. In mechanical keyboards and gaming mice, the switch can “bounce” several times when pressed, causing the device to register multiple inputs for a single press. Debounce time helps eliminate this issue by ignoring additional inputs that occur within a predetermined timeframe after the first press. However, the higher the debounce, the higher the delay of the registered “clicks.” Therefore, one aims to have as low a debounce as possible without “double clicks.”