Raw Input and Mouse Acceleration: Why Conversions Can Drift

Raw Input and Mouse Acceleration: Why Conversions Can Drift

Raw input and mouse acceleration matter because they control what the game receives before sensitivity math is applied. If the input path changes between games, the same converted value can measure differently or feel inconsistent.

In 2026, Microsoft Learn's "Raw Input Overview" says Raw Input lets applications get data directly from the device and process that data for their needs (Microsoft Learn, "Raw Input Overview"). For sensitivity conversion, that direct device path is exactly what you want.

Key Takeaways

  • Raw input helps a game read mouse movement directly.
  • Acceleration can make speed affect distance, which hurts repeatability.
  • Conversion should start with DPI, raw input, and acceleration checks.
  • If a match drifts, measure cm/360 before changing your sensitivity.

What Is Raw Input?

Raw input is a way for software to read device movement more directly instead of only receiving processed pointer movement. In FPS terms, it helps the game respond to mouse counts rather than desktop cursor behavior.

Microsoft Learn's "WM_INPUT message" explains that WM_INPUT is sent to the window receiving raw input and that raw input is available after an application registers devices with RegisterRawInputDevices (Microsoft Learn, "WM_INPUT message"). That is technical, but the player-facing idea is simple: the game asks for mouse data, then turns it into camera rotation.

For conversion basics, start with the mouse sensitivity conversion guide. For the rotation scale side, see what yaw means in mouse sensitivity.

What Is Mouse Acceleration?

Mouse acceleration changes output based on movement speed. Move the same physical distance slowly and quickly, and the cursor or camera may travel different distances.

MDN's "Pointer Lock API" notes that operating systems enable mouse acceleration by default and that first-person games often prefer raw mouse input, where the same distance produces the same rotation whether the movement is fast or slow (MDN, "Pointer Lock API").

That is why acceleration is risky for conversion. A converter assumes repeatable distance. Acceleration changes the relationship between distance and rotation.

Why Acceleration Makes Conversions Feel Wrong

Sensitivity conversion works best when input is linear. If 10 cm gives one amount of rotation, another 10 cm should give the same amount again. Acceleration bends that rule.

Here is the practical failure pattern:

  1. You convert from Game A to Game B.
  2. Slow tracking feels close.
  3. Fast flicks overshoot or undershoot.
  4. You lower or raise sensitivity to compensate.
  5. Slow tracking now feels wrong.

That loop usually means you are fixing the wrong layer. Check raw input and acceleration first, then test why converted sensitivity feels different.

What Should You Check in Windows?

Check Windows pointer behavior when the target game does not clearly use raw input. In 2026, Valve's June 2026 Steam Hardware & Software Survey reported Windows at 94.10% among surveyed Steam users (Valve, "Steam Hardware & Software Survey: June 2026"). That makes Windows mouse behavior relevant for most PC players in this audience.

Use this checklist:

If the game has a raw input option, test with it enabled first. If the game does not expose raw input, measure the result instead of assuming.

How Polling Rate Fits In

Polling rate is how often the mouse reports movement. It is not the same as DPI or sensitivity. Microsoft Learn says buffered raw input reads can be useful for high-frequency devices such as mice at 1000Hz (Microsoft Learn, "Raw Input Overview").

For most players, polling rate changes feel more than math. A conversion should not need a new sensitivity just because you moved from 500Hz to 1000Hz, but a different polling setup can change smoothness, latency feel, or how stable your hand feels.

How to Test Whether Input Is the Problem

Use a repeatable cm/360 test:

  1. Put your mouse at the left edge of a measured line.
  2. Face a fixed mark in game.
  3. Move the mouse the same distance at slow, medium, and fast speeds.
  4. Watch whether the camera reaches the same angle each time.
  5. Repeat after toggling raw input or acceleration settings.

If fast movement turns farther than slow movement, acceleration or input processing may be involved. If every speed lands in the same place but the game still feels strange, look at FOV and ADS with FOV and ADS sensitivity conversion.

Use this baseline before converting:

This keeps the converter focused on the intended job: translating physical turn distance between game scales.

Frequently Asked Questions

Should raw input be on for FPS sensitivity conversion?

Usually yes. Raw input helps the game read mouse movement directly instead of relying on desktop pointer behavior.

Can mouse acceleration ruin a conversion?

Yes. Acceleration can make fast and slow movements travel different camera distances, even when the same cm/360 value is entered.

What is the first setting to check?

Check the game's raw input option first, then Windows pointer acceleration and any mouse software acceleration settings.

Does raw input ignore Windows sensitivity?

Often, yes, but implementation depends on the game. Raw input is designed to let software read device data directly. If a game does not document its input path, test cm/360 manually.

Should I turn off mouse acceleration for every game?

For FPS conversion, yes as a starting point. Acceleration can be a personal preference, but it makes cross-game matching harder because movement speed changes the result.

Is polling rate part of eDPI?

No. eDPI is usually DPI multiplied by in-game sensitivity inside a game family. Polling rate affects reporting frequency, not the sensitivity value itself. For eDPI limits, read eDPI vs cm/360.

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