Sensor and Performance

The Mad Catz R.A.T. DWS is equipped with the PixArt PAW3335. According to specifications, the 3335 is capable of up to 16,000 CPI, as well as a maximum tracking speed of 400 IPS, which equals 10.16 m/s. Out of the box, four pre-defined CPI steps are available: 800, 1600, 3200, and 16,000.

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 decently low but inconsistent, which is a decent 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 R.A.T. DWS is moved first and thus receives a slight head start.

Since the R.A.T. DWS lacks wired connectivity, establishing wired performance is not possible. 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 16,000 CPI—to quickly gauge whether there is any smoothing, which would be indicated by any visible "kinks." As you can see, while no such kinks are visible in the 1600 CPI plot, they are plainly on display in the 16,000 CPI plot, indicating smoothing. Aside from the odd outlier, general tracking is fairly decent.


In order to determine motion delay, I'm looking at xSum plots generated at 1600, 6100, and 16,000 CPI. The line further to the left denotes the sensor with less motion delay. At 1600 CPI, I can measure a motion delay differential of roughly 1 ms. Smoothing is first introduced at 6100 CPI, resulting in a motion delay differential of roughly 2 ms. Smoothing is increased past the 10,000 CPI mark, topping out at 3 ms at 16,000 CPI.

Speed-related Accuracy Variance (SRAV)

What people typically mean when they talk about "acceleration" is speed-related accuracy variance (or 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 4.5 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 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. Aside from the odd outlier, I'm unable to detect anything that would be indicative of desynchronization drift.



Second, I'm testing the general polling-rate stability of the individual polling rates in wireless mode. Running the R.A.T. DWS at a lower polling rate can have the benefit of extending battery life. While polling is generally stable on the R.A.T. DWS, there are occasionally exceptions. That is, while polling will be perfectly stable at one point, it can break just a moment later, as shown below:


I'm unable to determine the reason for this fairly odd yet infrequent behavior.

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 or 3200 CPI. 16,000 CPI only has moderate jitter, which is impressive given how little smoothing is present. Lastly, there is no sensor lens movement.

Lift-off Distance

The R.A.T. DWS does not support LOD adjustment. This is unfortunate, as the 3335 would be fully capable of it. The sensor does not track at a height of 1 DVD (<1.2 mm). 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 is 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 +3.7 ms when compared to the Razer Viper 8K, which is considered as the baseline with 0 ms. Standard deviation is 2.4 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. Comparison data comes from my own testing and has been exclusively gathered with the LDAT.