Effective sensitivity (eDPI) — the number that actually matters
Also searched as: edpi · effective dpi · effective sensitivity · true sensitivity · match sensitivity · matching sensitivity · sensitivity matching
What it means
How far your aim swings isn't set by mouse DPI alone or in-game sensitivity alone — it's the two multiplied together, often called eDPI (mouse DPI × in-game sensitivity). That combined number decides how far your view turns for a given hand movement, so it's the thing worth keeping consistent — not the DPI dial on its own.
More detail
Because the feel comes from the product of the two, a 400-DPI / 2.0-sensitivity setup and an 800-DPI / 1.0-sensitivity setup aim identically — same eDPI, same swing. That's why, when you copy someone's settings, you match their eDPI rather than just their DPI: change one number and adjust the other to keep the product the same and your aim doesn't move. …
In the Blackbook
The deeper explanation continues inside the app. The Blackbook publishes its verdicts here — the full write-ups stay in the book, on your rig, next to your own measurements.
The Compy Blackbook holds 191 graded entries like this one, judged against your hardware — and every change it does make is reversible, with the receipt to prove it.
See Compy →