4000Hz & 8000Hz Polling Rate: Lower Delay, Higher CPU Load

Polling rate is the maximum number of times per second the mouse can send its latest movement to the PC. At 1000 Hz that is one report every 1.0 ms, at 2000 Hz every 0.5 ms, at 4000 Hz every 0.25 ms, and at 8000 Hz every 0.125 ms.

A mouse only reports when it has something to say. A still mouse sends little or nothing, so the rate you select is a ceiling, not a guaranteed stream. During fast movement an 8000 Hz mouse can ask the system to handle up to 8,000 reports per second.

Each report is processed through the USB controller and the operating system's input path. That costs some CPU time, and higher rates mean more of it. How much depends on the CPU, the game, the USB path, the mouse firmware, and how fast you move. On a strong CPU the cost can be hard to notice. On older or weaker CPUs, especially in CPU-bound games, some players see lower average FPS, worse 1% Lows, or visible frametime spikes during fast mouse movement. Games like CS2 and Valorant usually run at very high frame rates, which keeps the CPU busy and makes them a typical place where this overhead can show up.

Because the result varies so much between systems, there is no single number that applies to everyone. Treat reports of big FPS losses or "no loss at all" as results for one specific PC and test your own.

A sensor generates movement counts equal to how fast you move multiplied by your DPI. Roughly, counts per second = hand speed in inches per second x DPI.

To produce 8000 reports per second, the mouse needs to produce on the order of 8000 counts per second. At 800 DPI that takes about 10 inches per second of movement, at 1600 DPI about 5 inches per second, and at 400 DPI about 20 inches per second.

Slow tracking and small adjustments will often produce far fewer reports than the selected rate, while fast flicks and swipes get closer to it. Higher DPI makes it easier to keep a high polling rate busy.

Changing DPI does not change your sensitivity as long as you scale in-game sensitivity down by the same factor, so your eDPI stays the same.

Two things decide whether a high polling rate is stable in practice: how cleanly the mouse is connected, and whether your CPU has the headroom for it. If either is a problem, 1000 Hz remains a perfectly good setting.

What is well established: • Higher polling rates shorten the time between reports and increase the work done per second by the CPU and USB stack. • The effect on FPS and frametimes depends on the system. Some PCs show lower FPS or frametime spikes at 4K and 8K, and others show little change. • The benefit is largest for fast movement on high-refresh monitors with high frame rates. It shrinks when the game, display, or frame rate cannot use the extra timing resolution.

What is not established, and what this article does not claim: • We have not published benchmark numbers for specific CPUs, and you should be cautious about any article that gives exact FPS losses without a described test setup. • There is no universal rule such as "6-core CPUs fail at 8000 Hz" or "X3D CPUs are always fine." Game version, drivers, Windows settings, background software, and USB hardware all change the result.

The practical answer is to measure. The steps below give you a repeatable test.