Sensor and Performance

The Sharkoon Light² 100 is equipped with the PixArt PMW3325 sensor. According to specifications, the 3325 is capable of up to 5000 CPI, as well as a maximum tracking speed of 100 IPS, which equals 2.54 m/s. Out of the box, seven pre-defined CPI steps are available: 400, 800, 1200, 2400, 3200, 4000, and 5000.

Update January 24th:
Since the time of writing, a firmware update has been released that addresses the main flaw originally present on this mouse, which is the poor malfunction speed at higher CPI steps. It is strongly recommended to apply this firmware update. The following sections have been adjusted to properly reflect the changes made.

CPI Accuracy

"CPI" (short for counts per inch) describes the number of counts registered by the mouse if it is moved exactly an inch. There are several factors (firmware, mounting height of the sensor not meeting specifications, mouse feet thickness, mousing surface, among others) which may contribute to nominal CPI not matching actual CPI. It is impossible to always achieve a perfect match, but ideally, nominal and actual CPI should differ as little as possible. In this test, I'm determining whether this is the case or not. However, please keep in mind that said variance will still differ from unit to unit, so your mileage may vary.


I've restricted my testing to the four most common CPI steps, which are 400, 800, 1600, and 3200. As you can see, deviation is consistently negative and consistently massive. A very poor result overall. In order to account for the measured deviation, adjusted and mostly accurate steps of 400, 800, 1700, and 3400 CPI have been used.

Motion Delay

"Motion delay" encompasses all kinds of sensor lag. Any further sources of input delay will not be recorded in this test. The main thing I'll be looking for in this test is sensor smoothing, which describes an averaging of motion data across several capture frames in order to reduce jitter at higher CPI values, increasing motion delay along with it. The goal here is to have as little smoothing as possible. As there is no way to accurately measure motion delay absolutely, it can only be done by comparison with a control subject that has been determined to have the lowest possible motion delay. In this case the control subject is a G403, whose 3366 has no visible smoothing across the entire CPI range.


First, I'm looking at two xCounts plots—generated at 1600 and 5000 CPI—to quickly gauge whether there is any smoothing, which would be indicated by any visible "kinks." A small kink can be seen on both plots, but I doubt it's indicative of smoothing as the absolute level of jitter at higher steps suggests otherwise. What we can see, however, is relatively tight count distribution, although SPI timing jitter increases at higher speeds.


In order to determine motion delay, I'm looking at xSum plots generated at 400, 800, and 3200 CPI. The line further to the left denotes the sensor with less motion delay. I can measure a base delay of 2–2.5 ms at those three steps. This is largely in line with results for other 3325-equipped mice.

Speed-related Accuracy Variance (SRAV)

What people typically mean when they talk about "acceleration" is speed-related accuracy variance (or short SRAV). It's not about the mouse having a set amount of inherent positive or negative acceleration, but about the cursor not traveling the same distance if the mouse is moved the same physical distance at different speeds. The easiest way to test this is by comparison with a control subject that is known to have very low SRAV, which in this case is the G403. As you can see from the plot, no displacement between the two cursor paths can be observed, which confirms that SRAV is very low.

Perfect Control Speed

Perfect Control Speed (or PCS for short) is the maximum speed up to which the mouse and its sensor can be moved without the sensor malfunctioning in any way. Originally, the sensor in the Light² 100 was struggling massively in this test, but this has been rectified with the new firmware. Now, doing 4 m/s is no problem across the entire CPI range, which far exceeds specifications and is highly respectable for a 3325 (best in class).

Polling Rate Stability

All three available polling rates (125 Hz, 500 Hz, and 1000 Hz) look nice and stable.

Paint Test

This test is used to indicate any potential issues with angle snapping (non-native straightening of linear motion) and jitter, along with any sensor lens rattle. As you can see, no issues with angle snapping can be observed. No jitter is visible at 400 and 800 CPI. 1600 CPI already shows minor jitter, 3200 CPI even more. 5000 CPI has major jitter. Lastly, no sensor lens rattle can be observed.

Lift-off Distance

The Light² 100 offers no LOD adjustment options. At the default and only setting, the sensor does track at a height of 1 DVD, but not at a height of 2 DVDs (1.2<x<2.4 mm; x=LOD height). Keep in mind that LOD may vary slightly depending on the mousing surface (pad) it is being used on.

Click Latency

Since mechanical switches are being used for the buttons in most computer mice, debouncing is required in order to avoid unintended double clicks. Debouncing typically adds a delay (along with any potential processing delay), which shall be referred to as click latency. As there is no way to measure said delay directly, it has to be done by comparing it to a control subject, which in this case is the Logitech G100s. Using the latest 4 ms firmware, click latency has been measured to be roughly +3.9 ms when compared to the SteelSeries Ikari, which is considered as the baseline with 0 ms. Please keep in mind that the measured value is not the absolute click latency. Comparison data comes from this thread as well as my own testing, using qsxcv's program.