Sensor

As for the eye of the mouse, the G305 uses Logitech's HERO (High Efficiency Rated Optical) sensor. This one is pretty much on the same level as the current "flagship" PixArt PMW3366, but its power consumption is about 90% less than that model. Moreover, the HERO's framerate is highly variable, depending on its current tracking speed. This, of course, doesn't mean the sensor doesn't track well or isn't responsive when you make small and low-speed adjustments with the mouse. It doesn't have any smoothing, filtering or acceleration, as stated in its specifications on the official website.

The nominal maximum tracking speed and acceleration values are 400 IPS and 40 G. The resolution can be set from 200–12,000 CPI in increments of 50 CPI, and the available polling rates are 125, 250, 50, and 1000 Hz. There is an option to adjust angle snapping, but for gaming, I would highly suggest turning it off. The sensor did not track from 1 DVD in height (there is no option for lift-off distance adjustments as the HERO sensor does the calibrating automatically). The measurements were done on a plain black cloth mouse pad.

Paint Test

There is no jitter on the reasonable CPI steps, or unwanted angle snapping and measurable (or audible) sensor lens rattle.

CPI Divergence

There is no CPI divergence I could measure; all the CPI steps were totally exact. This is rare and, to be honest, very impressive at the same time.

Perfect Control Speed

The nominal tracking speed of the HERO sensor is ridiculously high at over 400 IPS or 10 meters per second. There is absolutely no chance of hitting that speed while in-game or anywhere within reasonable bounds.

Speed Related Accuracy Variance

This test shows the sensor's accuracy at different speeds. You can see me doing a fast swipe to the right before I slowly slide the mouse back to its original position. Any displacement is almost entirely caused by human error in this test.

Polling Rate

All set values seem to be perfectly stable; there are no suspicious outliers after multiple tests as those that can be seen are mere measurement errors.

Input Lag

There is next to zero input lag compared to a Ninox Venator at 800 CPI. This is utterly remarkable because we're talking about wired vs. wireless here. I cannot measure exact values, but it is definitely less than 1 ms, which means that it can easily be used for even high-level eSport gaming.