Sensor and Performance

The ASUS TUF M4 Wireless is equipped with the PixArt PAW3311. According to specifications, the 3311 is capable of up to 12,000 CPI, as well as a maximum tracking speed of 300 IPS, which equals 7.62 m/s. Out of the box, four pre-defined CPI steps are available: 400, 800, 1600, and 3200.

All testing was done on the latest firmware. As such, results obtained on earlier 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 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 decently low, which is a good result overall.

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. Note that the G403 is moved first and thus receives a slight head start.

Testing is restricted to 2.4 GHz mode as Bluetooth is not suitable for non-casual gaming applications.


First, I'm looking at two xCounts plots—generated at 1600 and 12,000 CPI—to quickly gauge whether there is any smoothing, which would be indicated by any visible "kinks." As you can see, such kinks are on display in the second plot, which indicates there being smoothing. SPI timing jitter is remarkably low.




The M4 Wireless has increased motion delay at the onset of motion, which is why I provide plots showing the onset, end, and entirety of the motion (left to right) for 1600, 5000, and 12,000 CPI (top to bottom). The line further to the left denotes the sensor with less motion delay. At 1600 CPI, the delay maintained throughout the motion is around 1.5 ms, whereas the onset delay is around 4 ms. At and above 5000 CPI, smoothing is applied, resulting in a motion delay of 8 ms throughout the motion and a delay of 10 ms at the onset, which holds true all the way until 12,000 CPI.

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. I've only managed to hit a measly 5 m/s (which is within the proclaimed PCS range), at which no sign of the sensor malfunctioning can be observed.

Polling Rate Stability

For wired mice, polling-rate stability merely concerns the wired connection between the mouse (SPI communication) and the USB. For wireless mice, another device that needs to be kept in sync between the first two is added to the mix: the wireless dongle/wireless receiver. I'm unable to measure all stages of the entire end-to-end signal chain individually, so testing polling-rate stability at the endpoint (the USB) has to suffice here.


First, I'm testing whether SPI, wireless, and USB communication are synchronized. Any of these being out of sync would be indicated by at least one 2 ms report, which would be the result of any desynchronization drift accumulated over time. As you can see, no off-period polls are visible, which has me believe that there is no desynchronization present.



Second, I'm testing the general polling-rate stability of the individual polling rates in wireless mode. Running the M4 Wireless at a lower polling rate can have the benefit of extending battery life. All of the available polling rates (125, 250, 500, and 1000 Hz) look and perform fine.

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 1600 CPI. 4900 CPI is the highest step without smoothing and shows little jitter that is then taken care of at 5000 CPI. 12,000 CPI displays surprisingly manageable levels of jitter. Lastly, there is no lens movement.

Lift-off Distance

The M4 Wireless does not offer any LOD adjustment. By default, the sensor does track at a height of 1 DVD (1.2<x<2.4 mm, x being LOD height), but not at a height of 2 DVDs. Keep in mind that LOD may vary slightly depending on the mousing surface (pad) it is being used on.

Click Latency

Most gaming mice use mechanical switches for their buttons. By wiring the switches of the test subject together with the switches of a control subject, I'm able to measure click latency very accurately; i.e., standard error of around 0.05 ms. However, this method is not applicable to mice with non-mechanical switches and wireless-only mice in general. As such, other methods ought to be employed, one of which being NVIDIA's Latency Display Analysis Tool (LDAT). The LDAT allows me to measure the entire end-to-end latency between the mouse click and photon transition on the monitor. By establishing the relative difference to a control subject, I'm able to provide values I consider sufficiently accurate; i.e., standard error of around 0.2 ms. Many thanks go to NVIDIA for providing me an LDAT v2 device.

Click latency has been measured to be roughly +5.2 ms when compared to the Razer Viper 8K, which is considered as the baseline with 0 ms. Standard deviation is 4.0 ms, but since the indicated value is neither the absolute click latency nor the measured end-to-end-latency, standard deviation ends up looking disproportionally large. That said, the standard deviation exceeds the usual level. Comparison data comes from my own testing and has been exclusively gathered with the LDAT.

The main button switches were measured to be running at 1.878 V. I'm not aware of the voltage specifications of the Kailh GM 4.0 (60 M) switches, but 1.878 V does seem rather low to me, albeit not excessively so.