Sensor and Performance

The ASUS TUF M3 is equipped with the PixArt PMW3325. 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. That said, ASUS found a way to up the maximum CPI to 7000 on the M3 and possibly tune the maximum tracking speed—more details below. Out of the box, six pre-defined CPI steps are available: 400, 800, 1600, 3200, 6400, and 10,000 CPI.

Disclaimer: All testing has been done with the most recent firmware (1.0.11). Results on previous firmware versions may differ from those presented hereafter.

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 actual CPI not matching nominal 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 vary from unit to unit, so your mileage may vary as well.


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 somewhat large at certain steps, but overall still acceptable. Compared to a previously tested firmware version, the improvement is tremendous. In order to account for the measured deviation, steps of 400, 800, 1500, and 3000 CPI have been used for testing. At least these corrected steps are pretty much spot on.

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 3200 CPI—to quickly gauge whether there is any smoothing, which would be indicated by any visible "kinks." Neither plot shows such kinks, but there are a couple of polling outliers on display. While this isn't perfect, it marks a massive improvement over the first firmware version I've tested.


Let us take a look at three xSum plots, generated at 1600, 3200, and 7000 CPI. The line further to the left denotes the sensor with less motion delay. At 1600 CPI, motion delay is 2.5–3 ms. This continues to be the case at both 3200 and 7000 CPI. In short, I can determine a flat motion delay of 2.5–3 ms across the entire CPI range.

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. Around 3.5 m/s, you can see the sensor malfunctioning. Although 3.5 m/s is above spec (~2.5 m/s), it's still pretty poor for today's standards.

Polling Rate Stability

The first firmware version I've tested did horribly in this regard. While there's still some variance, along with several outliers at higher speeds, polling stability is much better across all four available polling rates.

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. Both 400 and 1600 CPI show no jitter. 3200 CPI shows some, and 7000 CPI shows significant jitter. Overall it's quite reasonable across the board, however. Lastly, significant sensor lens rattle can be observed. For what it's worth, the second sample I've tested shows no sensor lens movement whatsoever.

Lift-off Distance

The M3 does not support adjusting LOD. The only available (default) setting is medium as the sensor does track at a height of 1 DVD, but not at a height of 2 DVDs (1.2 mm<x<2.4 mm). 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 G203. Click latency has been measured to be roughly +10.7 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.