Sensor and Performance

The Corsair Katar Pro Wireless 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, three pre-defined CPI steps are available: 800, 1500, and 3000.

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 vary 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 hardly consistent, but decently low across the board. 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 Katar Pro Wireless is moved first and thus receives a slight head start.

Since the Katar Pro Wireless lacks wired connectivity, establishing wired performance and thus determining the isolated wireless delay is not possible. Additionally, testing is restricted to 2.4 GHz mode as Bluetooth is not suitable for non-casual gaming applications.


First things first: The Katar Pro Wireless suffers from occasional polling outliers when running at a polling rate of 1000 Hz. The outliers are plainly on display in the first two plots. As shown below, 500 Hz shows no such issues.


Other than that, tracking is fairly clean, with no kinks indicative of smoothing anywhere in sight.


The three plots above were generated at 1600, 3200, and 10,000 CPI, respectively. The line further to the left denotes the sensor with less motion delay. Getting consistent motion delay results for the Katar Pro Wireless proved quite difficult, partly because of the aggressive power saving measures on the PMW3325 Corsair implemented. Essentially, there are two different types of rest mode. The first one is called Sleep Mode within iCUE and sets in after a certain period of time has passed, which is user-configurable. By default, the mouse enters sleep mode after 120 seconds have passed, and upon waking up, it'll take several seconds until the mouse again accepts any type of input. The second rest mode is native to the sensor. After a certain period of inactivity (typically around 10 seconds), the sensor enters a low power and low performance mode. As seen below, waking up from this mode takes roughly 70 ms.


I think there are further power saving mechanisms at work as well, simply due to the large variance in terms of sensor response. Often enough, the sensor picked up reporting counts with a significant delay or stopped reporting early.

In any case, the total motion delay appears to be in the realm of 3.5–4.5 ms. If we assume that wireless delay is equal to that of the Corsair Dark Core RGB Pro, effective sensor delay would be somewhere around 2.5–3.5 ms, which would be in line with results from other 3325-equipped mice. These figures only apply up until 5000 CPI—as seen in the last plot, any values above that are interpolated, resulting in much higher delay.

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. Right before hitting 4.0 m/s, the sensor malfunctions, as evidenced by the negative counts reported. While a PCS just shy of 4.0 m/s is above specification, it's still quite poor for today's standards.

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 don't have the means 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, several 2 ms reports are visible, which confirms that the polling of the entire signal chain is not in sync. Some of those 2 ms reports may be related to the polling outliers observed above, but their frequency indicates the presence of desynchronization drift.


Second, I'm testing general polling-rate stability of the individual polling rates in wireless mode. Running the Katar Pro Wireless at a lower polling rate can have the benefit of extending battery life. Apart from 1000 Hz, which can only be described as a mess, all polling rates are nice and stable. As such, I would recommend sticking to 500 Hz.

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, and 5000 CPI only shows minor jitter. 10,000 CPI is entirely interpolated and shows major jitter. Lastly, there is no sensor lens movement.

Lift-off Distance

The Katar Pro Wireless does not offer any LOD adjustment options. At the default, the only setting, the sensor does track at a height of 2 DVDs, but not at a height of 3 DVDs (2.4<x<3.6 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. For whatever reason, I cannot use my usual method with wireless-only mice. Using the less reliable and accurate "bump test," click latency has been measured to be around 1–2 ms higher than on 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.