Two numbers appear on almost every mouse specification: DPI and polling rate. They describe different things, and a larger number is not always an advantage.
DPI: how far the cursor moves
DPI means dots per inch. Sometimes it is written CPI, counts per inch. It tells you how many steps of movement the sensor reports when you move the mouse one inch across the desk. At 800 DPI, moving the mouse one inch sends 800 steps to the computer. At 1600 DPI it sends 1600, so the cursor travels roughly twice as far for the same hand movement.
That makes DPI a sensitivity setting, not a quality score. Office mice commonly sit between 800 and 1600. Gaming mice often list 12,000, 25,000 or more, but this top figure is a maximum that few users ever select. Many mice offer several DPI steps that you switch with a button.
Choosing a DPI
- A high-resolution monitor, such as 4K, needs more cursor travel, so a higher DPI feels more comfortable.
- A low DPI gives fine control and is common among players of games that require precise aiming.
- Your operating system and games have their own sensitivity sliders, which combine with the DPI.
Polling rate: how often the mouse reports
Polling rate, measured in hertz, is how many times per second the mouse sends its position to the computer. A 125 Hz mouse reports every 8 milliseconds. At 500 Hz it reports every 2 ms, and at 1000 Hz every 1 ms. Higher rates reduce the delay between moving the mouse and seeing the cursor move, and they make the movement slightly smoother.
Office mice often use 125 Hz, and gaming mice commonly use 1000 Hz. Some now offer 2000, 4000 or 8000 Hz. Gains beyond 1000 Hz are small and depend on a fast monitor and a computer able to process the extra data, which can use more processor time.
Wired and wireless
Older wireless mice added noticeable delay, but current models using a 2.4 GHz USB receiver can match wired mice closely. Bluetooth mice are convenient and need no receiver, but their reporting rate is usually lower. A higher polling rate also drains the battery faster on a wireless mouse.
Other specification items
Weight, shape, the number of buttons and the sensor type affect comfort and tracking more than a very high DPI figure. A small mouse suits a small hand or a travel bag; a larger one supports a full palm grip. Check the number of programmable buttons if you want shortcuts, and read the battery type for wireless models.