Sensor and Performance

The Darmoshark M3 4K is equipped with the PixArt PAW3395. According to specifications, the 3395 is capable of up to 26,000 CPI, as well as a maximum tracking speed of 650 IPS, which equals 16.51 m/s. Out of the box, five pre-defined CPI steps are available: 400, 800, 1600, 3200, and 4800.

All testing was done on the firmware version 00.00.23.00. As such, results obtained on other 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. Deviation is consistently positive and low, which is a very good result overall. In order to account for the measured deviation, adjusted steps of 400, 800, 1550, and 3100 CPI have been used for testing.

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 without special equipment, it is done by comparison with a control subject that has been determined to have consistent and low motion delay. In this case, the control subject is a Logitech G403, whose PMW3366 sensor has no visible smoothing across the entire CPI range. Note that the G403 is moved first and thus receives a slight head start.

Wired testing

First, I'm looking at two xCounts plots—generated at 1600 and 26,000 CPI—to quickly gauge whether there is any smoothing, which would be indicated by any visible "kinks." With ripple control disabled, neither plot shows any kinks, strongly suggesting there not being any smoothing across the entire CPI range.


The M3 4K also allows enabling MotionSync, which effectively synchronizes SPI reads with USB polls, resulting in very low SPI timing jitter as seen above.



In order to determine motion delay, I'm looking at xSum plots generated at 1600 and 26,000 CPI, both without (first row) and with (second row) MotionSync. The line further to the left denotes the sensor with less motion delay. Without MotionSync, a motion delay differential of roughly 0.5 ms can be measured at 1600 and 26,000 CPI. With MotionSync, a motion delay differential of roughly 0.5 ms is added, amounting to 1 ms in total.

Wireless testing

Not much changes when running the M3 4K in wireless mode as SPI timing jitter and general tracking are virtually on the same level as when wired.


This also applies with MotionSync enabled.



Once again, 1600 and 26,000 CPI both without (first row) and with (second row) MotionSync are tested. Without MotionSync, a motion delay differential of roughly 0.5 ms can be measured at both 1600 and 26,000 CPI. With MotionSync, a motion delay differential of 0.5 ms is added once again, resulting in a total motion delay differential of roughly 1 ms.


Much like on the regular M3 before, a rather curious behavior previously encountered on several releases from Razer (DeathAdder V2 Pro, V3 Pro, Viper V2 Pro, Naga V2 Pro, among others) as well as the VAXEE XE Wireless, is present on the M3 4K as well. At any point during the motion, though typically towards the start, motion delay is increased by at least a single interval, which is maintained through the motion. This happens exclusively in wireless mode and regardless of whether MotionSync is active. On earlier firmware, this behavior could be encountered very frequently at 2000 Hz as well. I'm unable to reproduce this behavior consistently.


Upon closer inspection, it becomes clear that any of these shifts correlates with an off-period poll.

Speed-related Accuracy Variance (SRAV)

What people typically mean when they talk about "acceleration" is speed-related accuracy variance (SRAV for short). 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 and results in no observable signs of the sensor malfunctioning.

Polling Rate Stability

Considering the M3 4K is usable as a regular wired mouse as well, I'll be testing polling rate stability for both wired and wireless use.

Wired testing

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

Wireless testing
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. Periodic off-period polls are present, which may point towards a desynchronization drift.



Second, I'm testing the general polling-rate stability of the individual polling rates in wireless mode. Running the M3 4K at a lower polling rate can have the benefit of extending battery life. All of the available polling rates display periodic (1 ms interval) off-period polls, along with bursts of generally increased noise.

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. 26,000 CPI with ripple control disabled (second row) shows major jitter, which is only decently lessened by enabling ripple control (third row). Lastly, there is no sensor lens movement.

Lift-off Distance

The M3 4K offers two pre-defined LOD levels. At the "Low" setting, the sensor does not track at a height of 1 DVD (<1.2 mm). Using the "High" setting, the sensor does track at a height of 1 DVD (1.2 mm<x<2.4 mm, with 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

In most computer mice, debouncing is required to avoid double clicks, slam-clicks, or other unintended effects of switch bouncing. Debouncing typically adds a delay, which, along with any potential processing delay, shall be referred to as click latency. In order to measure click latency, the mouse has been interfaced with an NVIDIA LDAT (Latency Display Analysis Tool). Many thanks go to NVIDIA for providing an LDAT device. More specifically, the LDAT measures the time between the electrical activation of the left main button and the OS receiving the button-down message. Unless noted otherwise, the values presented in the graph refer to the lowest click latency possible on the mouse in question. If a comparison mouse is capable of both wired and wireless operation, only the result for wireless (2.4 GHz) operation will be listed.

In wired mode and using a debounce time of 0 ms, click latency has been measured to be roughly 0.5 ms, with standard deviation being 0.23 ms. In wired mode and using a debounce time of 8 ms, click latency has been measured to be roughly 7.5 ms, with standard deviation being 0.20 ms. In wireless mode at a polling rate of 1000 Hz and using a debounce time of 0 ms, click latency has been measured to be roughly 0.7 ms, with standard deviation being 0.34 ms. In wireless mode at a polling rate of 1000 Hz and using a debounce time of 8 ms, click latency has been measured to be roughly 7.6 ms, with standard deviation being 0.40 ms.

In wireless mode at a polling rate of 2000 Hz and using a debounce time of 0 ms, click latency has been measured to be roughly 0.6 ms, with standard deviation being 0.14 ms. Lastly, in wireless mode at a polling rate of 4000 Hz and using a debounce time of 0 ms, click latency has been measured to be roughly 0.5 ms, with standard deviation being 0.08 ms. Scaling is mostly linear.

The main button switches were measured to be running at 1.981 V. I'm not aware of the voltage specifications of the TTC Gold (60 M) switches, but find this voltage to be rather low.